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Sea Anchors on Monohulls

S/M-4 Cutter, “Taleisin”

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TALEISINS/M-4

Cutter, "Taleisin"

29' 6" x 9 Tons, Full Keel Cutter

12-Ft. Dia. BUORD Parachute

Force 11-12 Conditions

 

File S/M-4, obtained from Lin & Larry Pardey - Vessel name Taleisin, hailing port Victoria, B.C., cutter designed by Lyle Hess, LOA 29' 6" x LWL 27' 9" x Beam 10' 9" x Draft 5' 3" x 9 Tons - Full keel - Sea anchor: 12-ft. diameter BUORD on 250' x 5/8" dia. nylon three strand rode with Pardeys' own bridle arrangement and 1/2" galvanized swivel - No trip line - Deployed in 100 fathoms during a tropical cyclone about 100 miles off the Queensland coast, with sustained winds of 60-70 knots blowing contrary to the Australian Current, creating confused seas of 25' and greater - Drift was estimated to be about 15 n.m. during 56 hours at sea anchor.

The Pardeys are now cruising on board their new and larger boat, Taleisin. The sea anchor for Taleisin was a larger - 12-ft. diameter - BUORD parachute. On 1 November 1988, en route to Mooloolaba from Roslynne Bay (Queensland), Taleisin safely rode out a cyclonic depression off the Australian coast, hove-to the para-anchor and storm trysail, in the manner described in the previous file (S/M-3). In their latest book, Storm Tactics, Lin and Larry describe the storm as "an unseasonable typhoon rammed up against a ridge of high pressure." The wind was blowing contrary to the Australian current, near the Great Barrier Reef. Conditions were atrocious. From Storm Tactics:

We were forced to lie-to parachute anchor for over 56 hours in winds exceeding 70 knots. (Weather forecasters spoke of winds of 85 in our area). Wind blew against current in only 100 fathoms of water, creating breaking seas, which forced 400-foot freighters to heave-to. We have never before seen waves dangerous enough to stop ships. We could see two of them nearby, maneuvering to keep their bows into the seas for over 12 hours. Yet even in seas like this we were able to bring Taleisin through with the only damage limited to chafed lines, chafed nerves, and bruised bodies. Other sailors within 50 miles of us fared far worse; two lost their lives while using other tactics.

Sometime in those fifty-six hours there was a formidable jerk as "an extra strong gust and an extra steep sea combined to head the boat up and tack." This caused Lin, who was sleeping down below, without the lee cloth in place, to be thrown out of her bunk against the stove, banging up her teeth and ribs, fortunately not too badly, however. All in all, Taleisin, tough little ship, came through with flying colors. But Larry has since opted for a smaller 9-ft. diameter BUORD, which he considers more yielding and better suited to the use of the bridle and riding sail arrangement.

Again, the main idea behind the Pardey strategy is to create a turbulent field upwind, a "slick" that smooths the seas and robs the waves of a great deal of their power. The bridle is adjusted so that the boat lies about 50° off the wind, and the use of a riding sail (storm trysail, triple-reefed main, or combinations of other sails, depending on the particular hull and rig) increases the pressure of the wind on the boat.

The result is that boat, rode and sea anchor are, as a train, drift downwind at about 5/8 of a knot, churning up the sea and setting up the turbulent field ahead of the boat. Note that this is a little different from the traditional method of heaving to - the boat occasionally fore- reaching.

Again: The Pardey strategy requires square drift. The yacht should not zig-zag or fore-reach out of her protective slick. She must drift squarely downwind, her keel "scraping" the sea. Refer to Storm Tactics for more insights into the Pardey's method of heaving-to.

Sea Anchors on Monohulls

S/M-3 Pocket Cruiser, “Seraffyn”

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SERAFFYNS/M-3

Pocket Cruiser, "Seraffyn"

24' 7" x 5 Tons, Full Keel Cutter

9-Ft. Dia. BUORD Parachute

Force 8-10 Conditions

 

File S/M-3, derived from writings of Lin & Larry Pardey - See article on "Heaving To" in August '82 issue of Sail Magazine, also pages 268-274 of Seraffyn's Oriental Adventure (W.W. Norton & Co., 1983) and the Pardeys' book entitled Storm Tactics (Pardey Books, 1995) - Vessel name Seraffyn, pocket cruiser, built by Lawrence F. Pardey, LOA 24' 7" x LWL 22' 2" x Beam 8' 11" x Draft 4' 8" x 5 Tons - Full Keel - Sea anchor: 9-ft. diameter Naval Ordnance (BUORD) parachute on 250' x 5/8" nylon three strand rode with Pardeys' own bridle arrangement & 3/8" galvanized swivel - No trip line - Deployed in the Gulf of Papagayo off Mexico and in the North Pacific during storms with winds of 40-70 knots - Bridle arrangement held the bow 50° off the wind - Drift was estimated to be about 5/8 of a knot.

 

Blue water veterans Lin and Larry Pardey have been using para-anchors since 1970. The one they used on Seraffyn was BUORD MK 2 MODEL 3. This parachute is government surplus and has been in use by fishermen for decades. The canopy is fabricated from heavy, nylon mesh material and it has sixteen shroud lines of 1000 lb. Dupont braid. Patrick M. Royce, author of Sailing Illustrated, did a series of tests on this parachute in 1969 and nicknamed it Two Pennant Storm Anchor (see page 157 of Royce's Sailing Illustrated).

Your author refers to these parachutes as "BUORDS" because they were originally developed for anti-submarine warfare use by the Navy's former BUreau of ORDnances - now Naval Sea Systems Command. Carrier-based S-3 Viking aircraft use such small diameter, heavy gauge parachutes to deliver torpedoes and other ordnances from the air. On page 269 of Seraffyn's Oriental Adventure the Pardeys show two photographs of the BUORD MK 2 MODEL 3. There is also a picture of Larry Pardey holding one up on page 36 of Storm Tactics.

In their original article in SAIL, Lin and Larry reported using this para-anchor in conjunction with a steadying sail in the Gulf of Papagayo (off Mexico) in gale force winds. The steadying sail would luff and flog violently as the boat was frequently pulled head-to-wind. Then it would fill and the head of the boat would fall off. This cycle would repeat itself once every four or five minutes - an uncomfortable and noisy affair. So Larry Pardey later rigged up an adjustable fairlead that kept the bow some 45-50° off the wind, at the same time causing the triple-reefed main to fill quite nicely and dampen the roll. This made the boat heel and lie much more comfortably. As a bonus, Larry found that in this attitude (45-50° off the wind) the boat would "scrape her keel" as she slid slowly downwind, leaving in her turbulent wake a significant "slick" that smoothed the seas, lessening their effect on the boat and gear. "You would be amazed at how this slick breaks down waves and steals their power," wrote the Pardeys to your author. Here is an excerpt from subsequent correspondence (reproduced by permission):

We have a preference for the BUORD surplus chute because 1) it is heavily built, with shrouds on our's almost strong enough to lift Taleisin, 2) it can be purchased quite inexpensively second hand, 3) as it is heavy weight fabric it does not have a tendency to fill with wind when you are deploying it, 4) we have used it since 1970 without problems, and finally, 5) because its fabric stretches when unusual strains come on it, the fabric becomes porous and lets some water sieve through, this absorbs shock loads.

Add this to the stretch of the nylon anchor line and we feel that the catenary curve-effect of chains or weights is redundant. We prefer a dead simple system - no floats, no trip lines, no catenary chains. We are also concerned about the move to bigger and bigger chutes. The bigger they are, the harder they are to store, handle and use. We are not sure they stop drift much better - once a chute is 8 to 15 feet in diameter, the drifts recorded by us on our boats, and during tests with modern sailboats off the Cape of Storms [South Africa], showed that the drift rate with the relatively small BUORD chute was about the same as that listed throughout the Drag Device Data Base for boats using much larger chutes, a drift of between 5/8 and one knot. For monohulls laying at a hove-to position, a smaller chute, combined with the considerable drag of the keel, as shown in the diagram, will produce a wide, effective slick. We can see that multihulls laying head to wind would need the largest chute possible as only the sea anchor is working to create a protective slick.

A further thought on chain. As chafe in the bowroller or fairlead is a major concern with any nylon anchor rode (onshore or offshore), we have considered using a 30 foot length of chain for the inboard end of the rode. But as we have not yet done so, we can make no actual comment on this idea.

PARDEY BRIDLE ARRANGEMENT
PARDEY BRIDLE ARRANGEMENT

 

Sea anchor rode is led off the bow. Pennant line from cockpit winch causes the bow to lie 50° of the wind. Storm trysail is set and the tiller lashed to leeward. As the boat is pushed downwind her keel begins to shed vortices, which gradually merge into a turbulent field upstream. The intense mixing effect of this turbulence will tend to cancel molecular rotation - the stuff that waves are made of. Note that this strategy requires square drift. The boat must not forereach - sail out of her protective "slick." The Pardeys have practical suggestions for ensuring that it does not in their book, Storm Tactics - required reading.

To what extent does the turbulence generated by the square drift of the keel affect the shape and ferocity of the waves? The "slick" mentioned by Lin and Larry Pardey is not to be confused with the superficial effects of oil on the surface of the water. It is a more profound phenomenon. It has to do with the turbulent field created by a succession of vortices, technically known as the Von Karman Vortex Street.

Vortices are eddies, created by the motion of irregular shapes in fluids. They flow away from the boundary layer and gradually merge into a homogeneous turbulent field in which the turbulence in one part of the field is the same as that in any other part.

Since non-homogeneous ocean waves are created by the orbital rotation of water particles, anything that interferes with that rotation can have an effect in a seaway. Logically, and if the interference is great enough, the resulting turbulent field can de-stabilize - or at the very least smooth down - the wave formations directly ahead of the boat.

Sea Anchors on Monohulls

S/M-2 Little Harbor 40 Yawl

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MAMBOS/M-2

Little Harbor 40 Yawl

39'11" x 11 Tons, Full Keel & Centerboard

24-Ft. Dia. Parachute Sea Anchor

Force 9-10 Conditions

 

File S/M-2, obtained from Charles W. Turner, Marblehead MA. - Vessel name Mambo, hailing port Marblehead, Little Harbor 40 yawl, designed by Ted Hood, LOA 39' 11" x LWL 29' 7" x Beam 11' x 11 Tons - Full keel with bronze centerboard drawing 10' 6" when down, (draft 4' 3" with board raised at sea anchor) - Sea anchor: 24-ft. diameter cargo type parachute on 120' x 1" dia. three strand rode & 1/2" swivel - Full trip line - Deployed in 1964 in deep water, approx. midway between Bermuda and Nantucket Light, within the Gulf Stream, with the wind estimated at between 40-60 knots with seas 25' and greater - Vessel's bow yawed 10° - Drift was estimated to be 40 n.m. during 12 hours at sea anchor - mainly due to the motion of the Gulf Stream.

 

Chapter eighteen of Coles's Heavy Weather Sailing is entitled Twice Rolled Over. It is about the trials and tribulations of the 39-ft. centerboard yawl Doubloon, whose 3/4-inch-thick bronze centerboard was "bent about 30 degrees, probably when it hit the water as the yacht came back to even keel after the roll over." Doubloon was forced to run before 60-knot winds off the Carolina coast in the spring of 1964. The skipper, Joe Byars, tried a variety of traditional tactics in an effort to "keep the sea."

First, he tried running before the wind under bare poles. It worked for a while, but after taking five full smashes from astern (resulting in one crewmember being temporarily swept overboard) he changed course and put Doubloon on a broad reach, trying to work the boat out of the storm and the Gulf Stream.

This new tactic seemed to work for a while. Three hours later, however, the yacht was unexpectedly struck by a breaking wave and knocked down on her beam end.

Byars tried lying a-hull next. With her centerboard down Doubloon lay quietly with her bow some 70° off the wind for four hours. Then, suddenly, a wave broke and rolled her completely - 360-degrees in about five seconds. Six hours later she was smash-rolled for the second time. All the crew sustained injuries - Byars broke a rib - and there was havoc down below.

The next day the crew managed to improvise "sea anchors," one of which consisted of a working jib, with the head attached to the tack to create more drag. Two mattresses were also lashed onto the remains of the stern pulpit in order to create windage aft. Doubloon took no more knockdowns.

A few months later, in June 1964, another sailboat called Mambo, practically identical to Doubloon, encountered similar conditions in the same area of the Gulf Stream, but used a parachute sea anchor. Mambo was on the homeward leg of the Bermuda Race when, at daybreak, the wind freshened from the NE and quickly built up to Force-9. This was followed by a build-up of the seas, and it wasn't long before the waves were big enough to completely blanket the wind when Mambo was in a trough.

Mambo's skipper, Charles W. Turner of Marblehead, Massachusetts, a moderately experienced sailor, had the boat running before the seas initially. A short time later, as conditions continued to deteriorate, a trusted and more experienced crewmember suggested that it seemed high time to turn the boat around and face into it.

The decision was then made to try to heave-to in the traditional way - by using sails. However severe cross-waves made it impractical to do this.

Another crewmember then pointed to the 24-ft. diameter para-anchor on the cabin sole which the owner had purchased. He stated, "Since you had us practicing with that thing off Marblehead, why not try it now?" The skipper decided that this was a good time to try it, since the man who had ridiculed it in Marblehead now appeared to favor its use.

It took three tries to accomplish proper deployment. On the first attempt the parachute blew under the bow until the keel was on top of it. It was then pulled back, straightened out and again tried. This time it flew up in the air, reaching a position where a mizzen staysail would normally be flown. It was again recovered.

On the third attempt it stayed in the water and, as the boat drifted back, it was payed out to the full length of its line, with the trip line float right above it. The line was secured to a bow cleat, although they were not sure it would hold. Mambo then faced nicely into seas of about 25-30 ft. In this posture she rode out the rest of the storm safely, albeit cork-screwing annoyingly because of the cross-seas which were running up the troughs. Mambo, tethered to the 24-ft. diameter para-anchor, sustained no knockdowns or "barrel rolls" as did her sistership, Doubloon.

Sea Anchors on Monohulls

S/M-1 Canoe, “Tilikum” (Voss)

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TILIKUMS/M-1

Canoe, "Tilikum" (Voss)

32' x 1.5 Tons

22" Dia. Cone Type Sea Anchor

 

File S/M-1, derived from the writings of John Claus Voss and Norman Kenny Luxton - Vessel name Tilikum, converted Siwash Indian war canoe, hailing port Victoria B.C., LOA 32' x Beam 5' x Draft 36" x 1.5 Tons - Sea anchor, four-foot long, 22-inch diameter canvas cone used in conjunction with a mizzen sail - Deployed in numerous storms during voyage from Victoria B.C. (May 19, 1901) to Tahiti, Australia, South Africa, and finally England (September 2, 1904).

This is one of the earliest recorded cases of a small sailing vessel using a sea anchor to negotiate heavy weather offshore. Mention of the use of the device is made in The Venturesome Voyages Of Captain Voss and Luxton's Pacific Crossing (Gray's Publishing, 1968 and 1971). Both books have been out of print but Grafton Books has recently issued a reprint of the former, now entitled Venturesome Voyages, in its "Mariner's Library" series.

Little is known of the life of John Voss, the father of drag devices. He was born in about 1854, some say in Newfoundland, others Nova Scotia, and yet others Sweden. His seafaring life seems to have begun in 1877 when as a young man he went to sea in large sailing vessels. By 1901 he was a hardened seaman, having served as master on many sailing ships plying the fur trade from Victoria to Yokohama. Much controversy surrounds him in his later years. Some maintain that he was eventually lost at sea. It is more likely, however, that he died in San Francisco in 1922, while earning a living driving a bus there.

The vessel making the remarkable 1901-1904 circumnavigation was a converted 32-ft. Siwash Indian dugout which, according to her owner, had been in many Indian battles on the West Coast of British Columbia. She was given the name Tilikum, a Chinook word meaning "friend." During the voyage to the South Pacific the crew of the Tilikum consisted of John Claus Voss, captain, and Norman Kenny Luxton, mate. The two later fell out with each other. Voss's attitude toward the sea was a very conservative one. He was not one to take anything for granted out there and dealt with the unpredictable forces of nature in a cautious, methodical way.

Wrote Norman Luxton, "Voss's ideas were very much more scientific in weathering a storm... he knew his business, and he learned it by going easy. I only once ever saw Voss take a chance. He never gave a storm any benefit of any doubt, and he never sailed until he even lost a sheet, always anticipating trouble. Many's the hell he has given me for not taking in sail when perhaps I should have." (Luxton's Pacific Crossing.)

"Captain Voss Patent Sea And Surf Anchor." From a hand sketch believed to be Voss's own. (Courtesy of the Maritime Museum of British Columbia).
"Captain Voss Patent Sea And Surf Anchor." From a hand sketch believed to be Voss's own. (Courtesy of the Maritime Museum of British Columbia).

 Voss told Luxton about how he would heave-to in a storm on what he called, a "sea anchor." He had gotten the idea from an old sailor in the North Sea. Tilikum's sea anchor consisted of an iron barrel hoop about twenty two inches in diameter, with a four-foot canvas cone sewn on (see image).

It was used in a total of sixteen heavy gales during the three year circumnavigation. To quote Luxton, "Once, for seventeen days the Tilikum rode to such an appliance and a drag, and never shipped a cup of water. The weather was composed of samples of everything that the misnamed Pacific could put up."

Voss maintained that a stationary hull was better able to retain its buoyancy - rise to the seas. The same hull moving at speed through the water, he argued, was "held down by suction" and susceptible to great damage by boarding seas. In Venturesome Voyages he appendixed some twenty paragraphs of advice, where we find the following:

I will go a little further, claiming - and I have absolute confidence in doing so - that on no occasion while in charge of a vessel which was hove-to under storm sail in a violent gale, have I shipped a sea that caused any damage to ship or outfit, even though the storm sails had been carried away by the force of the wind. And the same applies to the small boats I have sailed on long cruises when they were hove-to under sea anchor and riding sail. (Venturesome Voyages, Grafton Books, 1989.)

Voss's philosophy was to go into a defensive posture - heave-to - long before the seas built too high or began breaking. Head sails were first dropped and the vessel made to head up into the seas. The sea anchor was then lowered and its cable let out. The heavy mizzen was then set as a riding sail. Thus, if the bow fell off to one side it could only yaw so far before the sea anchor and the mizzen brought it back to face into the teeth of the gale. Using this tactic, Voss and crew were able to survive a 1912 typhoon off the coast of Japan in Sea Queen, a little yawl, 19 feet on the waterline! The outer fringes of the typhoon lifted the roof off Yokohama Station and drove a large steamer ashore.

This idea of "a cone and a riding sail" has entered into the folklore of heavy weather tactics. To this day your authors receive inquiries about the so-called Voss method. Both the Coast Guard report (CG-D-20-87, Investigation of the Use of Drogues to Improve the Safety of Sailing Yachts) and the Wolfson RORC report have concluded that small, cone-type sea anchors are generally ineffective and unstable on their own. Both indicate the need for larger devices for use off the bow.

Earl Hinz renders a similar verdict in Understanding Sea Anchors And Drogues (Cornell Maritime Press, 1987). It has to be pointed out, also, that small conical sea anchors tend to put inordinate strains on rudders and their fittings as well.

Lin and Larry Pardey have modified and modernized Voss's method of heaving-to with great success on their own boats. They have replaced Voss's small conical sea anchor with a larger parachute-type device, and his canvas mizzen with a modern storm trysail. Using these they have ridden out various storms with success - see Files S/M-3 & 4.

In 1965 Tilikum was restored and moved into the Maritime Museum of British Columbia in Victoria's Bastion Square. She - and her crude drag devices - can be seen there today, along with some other famous sailboats, among them John "Hurricane" Guzzwell's Trekka. A fact-finding mission to the Maritime Museum of British Columbia is highly recommend (read good excuse for a wonderful little vacation).

From Seattle take the high speed ferry to the delightful port of Victoria, then relax and immerse yourself in the sights, sounds and smells of a seafaring past. Stand on the wharf, close your eyes, and you may imagine that you hear the clanging of ship's bells and the noise and commotion that surrounds the arrival of a big, three-masted bark, after a difficult passage from Yokohama. The gaunt, tired Captain Voss leans silently over the rail. The first mate shouts orders as men with salt-crusted beards furl and tidy sails from their lofty perches up in the sky. Waiting on the wharf are the wives and children of the seamen, dressed in the attire of the late 1800s. A seagull cries out. The last yardarm is secured. The ship coasts to a perfect docking. Lines are heaved ashore. If you press your imagination a little more you may even see the horse-drawn carts lined up on the wharf, the horses flicking their tails impatiently.

DB Reports

Praise for DDDB

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"Living to tell the tale is proof enough of a successful method. Victor Shane's concept to compile such information is to be congratulated, considering a lack of knowledge has existed for as long as the problem itself. I look forward to the day when such information becomes a basic fixture on all sea going vessels."

John Abernethy, Founder, Seabrake

 

"This is a valuable collection of information regarding the use of parachute-type sea anchors and various types of drogues on the sort of boats we use. The case histories are interesting and revealing. The author pioneered the use of former USN ordnance parachutes on multihulls, and founded the company based on that experience. But this is more than an argument for his product. It is an honest presentation of frightening experiences made more bearable by these devices. Highly recommended for anyone who goes to sea...."

Captain John Bonds, Executive Director, U.S. SAILING (Courtesy American Sailor, The News Magazine of U.S. Sailing)

 

"I read through virtually the entire book without stopping. The cases were fascinating. What really made the reading educational, however, was your immediate analysis of each case. It is not the ultimate success or lack of success that makes the case studies worthwhile, but the factors leading to the result. I would think that anyone considering a voyage offshore should read the DDDB before selecting a sea anchor or drogue. I hope that the publishing of this inspires more people to submit their case histories to you and enlarge the base of information."

Cameron Bright, Associate Editor, Ocean Navigator

 

"I have read the DDDB from its inception and believe that it is, in context, a valuable contribution to safety at sea."

Peter Bruce, Editor, Heavy Weather Sailing

 

"I think your research can be a great contribution to the safety of small vessels at sea. I would like to suggest that you might consider expanding the DDDB so that, in the future, one could access a new design or an existing vessel and pass an intelligent judgment on its behavior in gale force winds. I hold the opinion that the prismatic coefficient, location and shape of the maximum section, shape of the buttocks, shape of the keel, rig, and shape of the hull above the waterline all play an important role in the behavior of the vessel in gales and the probability of needing to deploy a drag device."

Thomas E. Colvin, Naval Architect

 

"Victor has done a great job with his Drag Device Data Base. We must all support his efforts. He needs as many records as he can get, both the successes and the relative failures. This record is a vital part of research into survival at sea."

Professor Noël Dilly, University of London

 

"At the Wolfson Unit we specialize, and have complete faith, in physical testing, difficulties, time scales and safety. This is usually conducted in a controlled environment, often with scale models. Correlation of test results with full scale experience is invaluable but often difficult to achieve. The DDDB provides a compilation of experience which supports our limited experimental data. Whilst our recommendations for yacht stability have been much publicized, our advice on the value of drogues and sea anchors appears to have been overlooked. The evidence in this publication should be brought to the attention of all who operate ocean going yachts and other small craft."

Barry Deakin, Wolfson Unit, University of Southampton, England

 

"Prior to reading your book on sea anchors and drogues, I had numerous misconceptions about storm survival tactics and deployment of drag devices. Your extensive documentation of case histories was a source of tremendous enlightenment. I will incorporate much of this information in future safety lectures."

Charles Hawley, Moderator & Speaker, Cruising World Safety Seminars

 

"I am very impressed with your work on drag devices and feel that your collection of actual incidents of blue water sailors using drag devices is very beneficial to the improvement of safety at sea. Your Fourth Edition is a fine book which I can highly recommend to blue water sailors who want to buy real insurance, and not simply the kind printed on paper."

Earl R. Hinz, Author, Understanding Sea Anchors and Drogues

 

"The DDDB is a real and important contribution to our knowledge of storm tactics. You are to be commended for organizing and maintaining the data collection process and for presenting the results in such a clear and useful fashion."

Donald J. Jordan, Co-Author, Investigation Of The Use Of Drogues to Improve The Safety Of Sailing Yachts (U.S. CG-D-20-87)

 

"There is ever more evidence that the catamaran configuration is rather more seaworthy than even the most enthusiastic of its proponents amongst us anticipated. In my view, the two items that will add the `seal' to the catamaran's place as a fully seaworthy, go-anywhere yacht are the drogue and the sea-anchor. No serious trans-ocean yacht should leave port without one. To go with the equipment we need to know how best to use it. Not something we can just go out and test - the DDDB is the next best thing. Keep up the good work."

Derek Kelsall, Kelsall Yacht Designs, Ltd.

 

"A very good effort!"

Richard Newick, Newick Multihulls

 

"Keep up the good work!"

Daniel C. Shewmon, Shewmon Sea Anchors, Inc.

 

DB Reports

About the sea

Quote

"Eternal Father, strong to save, whose arm has bound the restless wave...

O hear us when we cry to thee, for those in peril on the sea."

 William Whiting

 

"Every small vessel venturing offshore is a lonely entity, face to face with the most elemental force on the planet earth."

    Carleton Mitchell

 

"The sea drives truth into a man like salt."

 Hilaire Belloc

 

"The time to take measures for a ship's safety is while still able to do so. Nothing is more dangerous than for a seaman to be grudging in taking precautions, lest they turn out to have been unnecessary. Safety at sea, for a thousand years, has depended on exactly the opposite philosophy."

  Chester W. Nimitz,
Admiral, U.S. Navy

 

"At sea, man is always at war with the elements."

 Anonymous

 

"When the wind rises to Force 10 or more, and the gray beards ride over the ocean, we arrive at totally different conditions, and for yachts it is battle for survival, as indeed it sometimes may be for big ships."

     K. Adlard Coles

 

"The fallacy lies in expecting anything at sea to be as it `should be'."

     Webb Chiles

 

"In the 1979 race, the sea showed that it can be a deadly enemy, and that those who go to sea for pleasure must do so in the full knowledge that they may encounter dangers of the highest order."

Official Inquiry,  Fastnet tragedy of 1979

Sea Anchors on Catamarans

S/C-6B Catamaran, Crowther

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S/C-6B

Catamaran, Crowther

43' x 25' x 7.5 Tons

18-Ft. Dia. Sea Anchor

Force 10 Conditions

 

File S/C-6B, second file (see S/C-6A) obtained from Josh Tofield of Tucson, AZ. - SAME VESSEL - SAME SEA ANCHOR - SAME BRIDLE & TETHER DIMENSIONS - Deployed in a storm in deep water about 800 miles northeast of Hawaii with winds of 50-55 knots and seas of 25 ft. - Vessel's bow yawed 10° - Drift was 5 n.m. during 72 hours at sea anchor.

This is the second file involving Ariel. In the previous file she successfully rode out Force 8-9 conditions on the same parachute with a 250' tether. In this file we see that the 250' tether was clearly too short when Ariel ran into a much heavier storm on her way back from Hawaii. The 250' x 3/4" tether was not long enough to provide adequate shock absorption, as a result of which the boat took a severe pounding. Ariel's tether should have been at least 400' in this instance (the general rule of thumb being LOA x 10). Transcript:

Ariel departed Hawaii 11/10/91 with delivery skipper aboard. He has documented over 100,000 miles in deliveries for Compass Yacht Services alone. Approx. 800 miles NE of Honolulu a rapidly moving, intense LOW which was squeezing against a massive hi-pressure cell caught Ariel in the exact center of reinforced winds. Barometer dropped from 1018 to 1002 in 3 hours! (Weather Fax attached). Wind started one hour later and built to Force 10 where it stayed, never dropping below Force 9 in 48 hours. Waves were 25' (conservatively measured from the back of wave height and not from the troughs). Bridle (3/4" nylon) chafed completely through & had to be replaced with 5/8" backup bridle. Later one leg of the 5/8" bridle SNAPPED in the center when hit with very large wave, throwing Ariel backward, shearing the foam & fiberglass off of one rudder completely, and leaving only half of the other rudder (which later broke off). Crew eventually added 100-150' of anchor chain to the 250' of 3/4" nylon tether and rode out the rest of the storm.

Recovery, using the "partial trip line" was very difficult. Engines both out because during the storm, while motoring up to relieve pressure on bridle (while changing it) a large wave submerged entire stern, forcing water up exhaust system and drowning the engines (exhausts 2' above waterline under aft bridge deck !!!!!) Jury rigging done after storm passed. Ariel was then sailed 1500 miles to San Diego. Moral of the story: USE LOTS OF PRIMARY TETHER! What is adequate for Force 9 is not adequate for Force 10!

Sea Anchors on Catamarans

S/C-6A Catamaran, Crowther

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S/C-6A

Catamaran, Crowther

43' x 25' x 7.5 Tons

18-Ft. Dia. Sea Anchor

Force 9 Conditions

File S/C-6A, obtained from Josh Tofield, Tucson, AZ. - Vessel name Ariel, hailing port San Diego, catamaran, designed by Lock Crowther, LOA 43' x Beam 25' x Draft 3' 3" x 7.5 Tons - Sea anchor: 18-ft. Diameter Para-Tech on 250' x 3/4" nylon three strand tether and bridle arms of 75' each, with 5/8" galvanized swivel - Full trip line - Deployed in a tropical depression in deep water about 400 miles SE of Cabo San Lucas, Mexico, with winds of 45-60 knots and seas of 18 ft. - Vessel's bow yawed 10° - Drift was 2 n.m. during 20 hours at sea anchor (confirmed by GPS).

Several weeks after Ariel left San Diego for points south she ran into an unforecast loop of ITCZ - Inter Tropical Convergence Zone - at 21° 09' North, 106° 52' West. In his book, Weather For The Mariner, William J. Kotsch has this to say about the phenomena (Naval Institute Press, reproduced by permission):

     "The ITCZ is usually characterized by strong, ascending air currents, a great deal of cloudiness, and frequent heavy showers and thunderstorms. The intensity does, however, vary greatly. Sometimes the ITCZ looks like a tremendous wall of black clouds, with the top extending to 55,000 feet and higher.... The width of the ITCZ varies from about 20 to 150 nautical miles, and as a general rule, the narrower the zone (i.e., the greater the convergence), the more intense is the weather associated with it. When the ITCZ is near the equator, only small and weak cyclonic circulations can develop within it. But when it migrates away from the equator (at least five degrees or more), the influence of the earth's rotation becomes great enough to transfer sufficient "spin" to the converging air currents to permit tropical cyclones, hurricanes, and typhoons to develop."

One really needs a chart of Mexican waters to appreciate the value of a parachute sea anchor in tight quarters. Ariel was about 100 miles off the Mexican coast proper, with the rocky islands known as Tres Marias to her lee. The crew consisted of owner Josh Tofield, his wife, and two small children. Tofield deployed an 18-ft. diameter Para-Tech sea anchor and "anchored" Ariel to the surface of the sea.

Tres Marias is a Mexican prison compound. There is a 20-mile forbidden zone around it and pleasure boats have been known to be rammed by gunboats for intruding into the zone. It being dark, and apprehensive about getting too close to the islands, Josh Tofield kept a close eye on the GPS readings. Incredibly, he found that Ariel drifted no more than 2 nautical miles in the 20 hours that she was tethered to the sea anchor. Transcript:

Only 100 miles from Puerto Vallarta and with the Islas Tres Marias in our lee we got caught in a brief but fierce (unpredicted by WX or WXFAX) loop of ITCZ convection sucked up to our latitude. Winds of 45 knots sustained, gusts to 60 for 6-8 hours, with 30-35 knots sustained for 6-8 hours before and after. As long as the wind was blowing from the SE the seas were highest - but also most comfortable, as our catamaran rocked up and down in 18-ft. maximum seas, with 3-ft. breaking tops, and almost no side to side [yawing] motion. However, as the wind veered, large cross swell came under and slammed bridge & deck viciously - but no damage and no excess heeling.

My alternative would have been to run off to the West - which we could have done - but I didn't want to as we would have been blown all the way to Cabo before the wind subsided.

Only problem was the trip line. Perhaps I tied it on wrong to its small swivel, but it fouled fender severely and pulling in required anchor windlass and much bad language!

ADJUSTING BRIDLE FOR BEST RIDE.
ADJUSTING BRIDLE FOR BEST RIDE.

This is one of numerous files in which boats had problems with fouled up trip lines. Yet another reminder that FULL trip lines should be kept fairly taut at all times (see Fig. 39 and review last paragraph of file S/T-7). Also, the problem relating to cross swells mentioned by Tofield can in most instances be lessened by adjusting the lengths of the bridle arms on multihulls. By shortening one bridle arm and lengthening the other (Fig. 41) it is possible to rotate the bows into a direction more accommodating to changing sea conditions. If the wind and dominant waves have been coming from the north (0°), for example, and a secondary disturbance begins to squeeze in a different set of waves from the northeast (45°), the skipper may wish to adjust the bridle arms so that the bows are pointing somewhere in between the two sets of waves (about 22°).

Sea Anchors on Catamarans

S/C-5 Catamaran, Walter Greene

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S/C-5

Catamaran, Walter Greene

50' x 30' x 5 Tons

4-Ft. Dia. Sea Anchor

Force 9 Conditions

 

File S/C-5, obtained from Walter Greene, Yarmouth, ME. - Vessel name Sebago, catamaran, designed by Walter Greene, LOA 50' x Beam 30' x Draft 7' (20" board up) x 5 Tons - Sea anchor: 4-ft. Diameter Shewmon on 250' x 3/4" nylon braid tether and bridle arms of 50' each, with 1/2" galvanized swivel - No trip line - Deployed in a whole gale in deep water in the middle of the North Atlantic with winds of 40-50 knots and seas of 25-30 ft. - Vessel's bow yawed 45-60° - Drift was estimated to be 30 n.m. during 48 hours at sea anchor.

By way of a brief digression we should perhaps mention a previous experience of renowned multihull designer Walter Greene, an experience that ushered in a new era in SAR (search and rescue). Indeed the experience marked a point in maritime history when it became possible to ensure the safety and survival of human life at sea to an extent never before possible.

On 10 October 1982 Greene was sailing his 50' trimaran Gonzo to St. Malo, France, when it capsized in a violent North Atlantic storm 300 miles south-east of Cape Cod. The boat had been running before 30-ft. seas without a drogue when she was picked up and thrown by a huge wave - she broach-capsized when one of her bows dug into green water. Once over the initial shock of the capsize, Greene and his well-prepared crew jumped into action. In no time they had donned their immersion suits, lashed themselves to the upturned, floating, hull, and switched on the EPIRB - Emergency Position Indicating Radio Beacon.

It was the navigation officer on board TWA's flight 904 that first heard the lonely wailing of Gonzo's EPIRB (the signal is swept audio tone, sounding like a miniature "wow-wow" police siren). The information was immediately relayed to the FAA's Oceanic Control at Islip, New York, which in turn informed Atlantic Rescue at Scott Air Force Base in Illinois.

At that time (1982) SARSAT - Search And Rescue Satellite-Aided Tracking - was not quite operational, but a participating Russian satellite, Cospas, was known to be overhead. Scott AFB obtained an uplink and sure enough, no sooner had Cospas signed on than it confirmed a "hit." The satellite then provided data and telemetry needed to pinpoint the position of the distressed vessel. Atlantic Rescue then broadcast an urgent All Ships Bulletin, and the tanker California Getty was diverted to the scene. At the same time, the Coast Guard Air Station at Elizabeth City North Carolina was briefed and advised to launch a C-130 search plane, which picked up Gonzo's EPIRB signal, homed in on it and dropped two datum marker buoys (which transmit additional homing signals on a different frequency).

The tanker California Getty was the first on the scene, but failed to effect safe rescue in the 25 ft. seas, standing off to windward to provide a "breakwater" for the disabled trimaran. And there she stayed, "like a big Saint Bernard," until the 210' Coast Guard Cutter Vigorous arrived on the scene.

One by one the three survivors were taken off to safety, concluding one of the most remarkable rescues in maritime history -one of the first in which a satellite played an instrumental role. (A quick reminder that SARSAT is now fully operational in most areas of the world and any sailor with a Class A EPIRB can access the grid to get a distress signal through to international Search & Rescue agencies).

Walter Greene happily went on to design many more multihulls and four years later used a sea anchor on board his 50' catamaran, the infamous Sebago. The 4-ft. diameter Shewmon sea anchor was deployed off the bow, but was too small to do a satisfactory job (the same sea anchor did a lot better when used off the stern - see file D/C-1.) The bows of the big catamaran yawed past 60° at times.

Shewmon sea anchors are available in many sizes, up to 33 feet in diameter. Literature published by Shewmon, Inc. would seem to indicate the need for an 8-10 ft. diameter Shewmon sea anchor for a boat the size and weight of Greene's Sebago.

Why did Walter Greene choose a 4-ft. diameter sea anchor instead? Likely he was worried about a bigger one being too "unyielding." Victor Shane ran into this same apprehension among other multihull sailors. To this day some of them will react with alarm at the very idea of tethering their boats to a large diameter, "unyielding" sea anchor in a gale.

Sea Anchors on Catamarans

S/C-4 Catamaran

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S/C-4

Catamaran

40' x 20' x 3.5 Tons

12-Ft. Dia. Parachute

Force 7 Conditions

 

File S/C-4, obtained from Sackville J. Currie, Blaney, Ireland - Vessel name and design unspecified, hailing port Tokyo, catamaran, LOA 40' x Beam 27' x Draft 6' x 3.5 Tons - Sea anchor: 12-ft. Diameter Para-Tech on 60' x 1/2" nylon braid with 1/2" galvanized swivel - Emergency deployment when the windward ama broke off in shallow water (100 fathoms) five miles off Cape Nojima, Japan, with winds of 30 knots and confused seas of 12-15 ft. - Occupants were taken off by a Japanese Coast Guard helicopter.

File S/C-4 illustrates the value of a sea anchor in one of many likely damage control situations. En route to Sendai this 40-ft. catamaran sailed out of Tokyo Bay and, rounding Cape Nojima to head north, ran into 30-knot winds blowing contrary to a local current.

After considerable heavy labor against 12-15' steep, confused and choppy seas the windward pontoon suddenly broke off, leaving the catamaran lame and disabled seven miles offshore, now rapidly drifting out into the open sea.

The owner's main concern was that the boat might tack and, with the one ama broken off, capsize. He immediately deployed a 12-ft. diameter Para-Tech sea anchor off the bow of the remaining hull. The sea anchor held the lame boat more or less head-to-sea, preventing capsize and at the same time keeping the crippled vessel from drifting out of the shipping lanes and into the great Pacific. With the situation temporarily stabilized and the motion of the yacht eased, distress flares were then launched which were spotted by a passing freighter. The captain of the freighter radioed the Japanese Coast Guard, which sent a helicopter to the scene and plucked the survivors off the multihull. The boat was then abandoned to the raging seas, still tethered to its 12-ft. diameter, orange-colored parachute sea anchor.