File S/C-7, obtained from Roger Ayers, Ft. Lauderdale, FL. - Vessel name Marney, hailing port Ft. Lauderdale, catamaran ketch, designed by James Wharram, LOA 35' x Beam 17' x Draft 2' 6" x 3 Tons - Sea anchor: 9-ft. Diameter BUORD on 300' x 1/2" nylon three strand tether and bridle arms of 25' each, with 1/2" galvanized swivel - No trip line - Deployed in a low system in 100 fathoms about 25 miles east Cape May, with winds of 35-45 knots and seas of 10-12 ft. - Vessel's bow yawed 30° - Drift was estimated to be 12 n.m. during 6 hours at sea anchor.
Marney, a 35-ft. Wharram "Tangaroa" was home-built by Roger and Marney Ayres, who have been chartering, delivering and crewing yachts on the east coast, the Caribbean and Europe. In June '85 they were sailing her to Florida when they were overtaken by a frontal system off the coast of New Jersey. The wind was blowing Force 7-8, contrary to a southerly current, producing steep, short-duration seas of 10-12 ft. They deployed a 9-ft. diameter BUORD. The parachute was not big enough to do an adequate job of keeping Marney pointed into the seas. Her twin bows were yawing about 30° off to each side - through an arc of 60°. The rudders seemed to be under inordinate strain as well. Transcript:
We were caught departing from Cape May with a good forecast of 10-15 knots. As the afternoon wore on and we reached out, the wind freshened. We decided to beat as far offshore as possible, which we did, finally reduced to storm staysail and a double-reefed main. In this, our first real blow in this boat, we were not operating as "professionally" as we might have, and concerned ourselves only with getting offshore in case the wind backed further to the east, not noting our exact position, etc. just beating on [trying to gain ground].
The sea anchor was deployed from the bows, but allowed too much leeward drift (estimated 2-3 knots), and also allowed us to fall back off the steep, short seas, which had built up in the southerly current. I think that falling back off a larger 15 ft. wave at an angle, we broke both tillers. Note that a catamaran with two large transom-hung rudders, when backing into a trough and burying the sterns, exposes two blades, and two sets of cheeks to the force of the water, approximately 4 times the area of a typical trimaran spade rudder. It is therefore essential that this type of boat (like a Wharram) make no sternway, else use the sea anchor off the stern.
We are saving the BUORD for use as a "lunch hook," but now have a 24' diameter parachute for use off the bow.
File S/M-14, obtained from Walter Keintzel, Monterey, CA. - Vessel name Deanna, hailing port Monterey, "Carol" double-ender designed by Chuck Paine, LOA 24' 6" x LWL 20' x Beam 9' x Draft 3' 6" x 2.7 Tons - Full keel - Sea anchor: 9-ft. diameter BUORD on 300' x 1/2" nylon three strand with 1/2" galvanized swivel - Deployed in deep water off the central coast of California in low system with winds of 30 knots and seas of 10 feet - Vessel's bow yawed up to 80° - Drift was about 7 miles during 11 hours at sea anchor.
Victor Shane had the opportunity to take a close look at Deanna when she was moored in Santa Barbara harbor. This little pocket cruiser has a flush deck, with very low freeboard and a large full keel beneath. When Deanna is lying a-hull she is more or less anchored to the surface of the ocean by virtue of her big keel alone. Her rate of drift is further reduced because of her low freeboard. In general a yacht has to drift, to tug at a sea anchor, to cause it to fully inflate and function properly. In 60-knots of wind the same BUORD would have done a better job on this boat. A much larger parachute, say a 24-ft. diameter military chest reserve, would likely have pulled Deanna's bow up much higher into the wind as well, even in the given 30 knots. Here is a transcript of the feedback obtained from Walter Keintzel:
Location was 55 miles true west of Pt. Sal, measured by the Loran. I don't recall the barometer reading, but it was "normal." Don't recall the wave length & period, because when I deployed the sea anchor at 20:00 hrs. I was very, very exhausted & numb.
We lay at 80° to the nylon rode - almost parallel to the seas. I think this is because my flush-decked boat got lost in the troughs - not enough windage! With a riding sail on the back stay, I think it would work. As it was, it wasn't too bad.
Mainly the anchor kept me in place for a stormy night, and kept my physical condition from deteriorating to the point where I needed to call the Coast Guard. Next day I ran into Morro Bay for rest & repairs.
I'm very grateful for the parachute anchor. It was easy to deploy, but next time I'll certainly use a 300' trip line. Retrieval was like pulling a VW for fifty minutes!
File S/M-13, obtained from Gary Kaye, Sidney B.C. - Vessel name Mintaka II, hailing port Vancouver B.C., designed by Lyle Hess, LOA 37' (with long bowsprit) x LWL 26' x Beam 10' x Draft 5' x 7 Tons - Full keel - Sea anchor: 9-ft. diameter BUORD on 300' x 5/8" nylon three strand rode with 1/2" galvanized swivel - No trip line - Deployed in a whole gale in deep water approx. 140 miles west of Coos Bay (Oregon coast) with wind sustained at 40 knots and seas of 20 ft. - Use of the "Pardey Bridle" arrangement held the bow 50° off the wind. Drift was estimated to be about 50 n.m. during 52 hours at sea anchor.
In August 1987 Mintaka, a Lyle Hess designed Bristol Channel Cutter, was headed for San Francisco from Victoria B.C., when she ran into a whole gale at about latitude 44° N, longitude 127° W, (some 140 nautical miles west of the Oregon Coast). Gary and Sandi Kaye deployed a 9-ft. diameter BUORD parachute, using the Pardey bridling method (see files S/M-3, 4). All told, this traditionally designed, heavily built cruising yacht was hove-to for 52 hours, the wind sustained at 40 knots and seas of 20 feet.
Since there were no written notes, opinions or observations accompanying the DDDB form that Victor Shane received from these intrepid sailors, it was likely a matter of routine seamanship. Victoria, has a rich seafaring history. It is the hailing port of Taleisin, as well as a number of other boats in this database. It is inspiring to find boats like Mintaka following in the Voss/Pardey tradition of safe voyaging under mast and canvas. When one of these boats get into heavy weather the crew members are not wanting for a tactic. They heave-to, ride out the storm, and quietly resume their cruising.
File S/M-9, obtained from Captain Jerry Sidock, Fort Myers Beach, FL. - Vessel name Bounty Hunter, hailing port Fort Myers Beach, Hunter sloop, designed by Warren Luhrs, LOA 40' x LWL 32' 6" x Beam 13' 6" x Draft 5' x 9 Tons - Fin keel - Sea anchor: 9-ft. Diameter BUORD on 300' x 5/8" nylon three strand rode with 1/2" stainless steel swivel - Full trip line - Deployed in a gale in shallow water about 100 miles off the coast of Venezuela, with winds of 40-50 knots and seas of 15 feet - Vessel's bow yawed 20°-30° off to each side - Drift was 11 n.m. (confirmed by Loran & Satnav) during 14 hours at sea anchor.
Bounty Hunter, a fin-keeled Hunter 40, was on her way to Rio from Florida when she ran into a gale some 100 miles off the coast of Venezuela. The owner of the boat, Captain Jerry Sidock, being single-handed and tired at the time, deployed a 9-ft. BUORD off the bow. In one of several telephone conversations with Victor Shane, Captain Sidock reported that the bow held into the seas in a satisfactory way, yawing as she would at ground anchor, 20-30° off to each side, but certainly no more than 30°.
Note the same parachute sea anchor being used by different boats with varying results. Compare Bounty Hunter's underwater profile with those of the Pilot Cutter and the Vancouver 27 in the preceding files. Bounty Hunter has a more symmetrical underwater profile, her center of lateral resistance being a little closer to the center of effort of her rig. Additionally she was in stronger winds as well. Note however that her bow did yaw up to 30° off to each side, indicating that the yacht could do with a larger sea anchor
Captain Sidock knows the Caribbean Islands well. In his voyages to the Caymans, Jamaica, Roatan, Belize, Honduras, Guatemala and South America he often uses the BUORD off the stern for rest periods. There is then hardly any side-to-side yaw at all.
Note that there is nothing wrong with using a sea anchor off the stern for rest and recuperation, drift control and damage control in moderate conditions. Moreover, for non heavy weather use the rode need not be very long either. Deploy the parachute, pay out a hundred feet of line and cleat it off. Now you can rig the awning over the boom, prepare a meal in peace and relax for a while, the whole ocean your own private anchorage. From Captain Sidock's handwritten feedback:
I would like to say that I don't think that common sense would permit me to leave shore without my sea anchor. It is just too difficult at times to continue on when short-handed, or rather single-handed, as I am most of the time. It is at that time that I look for assistance from other sources, such as a sea anchor.
File S/M-8, obtained from Anthony Gibb, Victoria, B.C. - Vessel name Hejira, hailing port Victoria, Vancouver cutter, designed by Robert Harris, LOA 27' x LWL 22' x Beam 8' 6" x Draft 4' x 5 Tons - Full keel & cutaway forefoot - Sea anchor: 9-ft. diameter BUORD on 275' x 1/2" nylon three strand rode with 1/2" galvanized swivel - No trip line - Deployed during passage of frontal trough In deep water in the Tasman Sea with winds of 35 knots and confused seas of 12 feet - Vessel's bow yawed as much as 90° off to each side.
Hejira, a Harris-designed Vancouver 27 on a world cruise, crossed from Nelson, New Zealand, to Sydney, Australia in 15 days, a distance of 1,265 miles.
As with most other crossings of the Tasman this one was not a pleasant one. The crew was harassed by a confusion of waves and swells from both southwest and northeast, which harassment did not end until the last two days of the crossing.
During a period of 30-35 knot south-westerly winds and 12-foot seas the crew deployed a 9-ft. diameter BUORD. As in the previous file, the parachute did not do a satisfactory job. Transcript:
The BUORD never set straight forward off the bow. It remained directly off the beam. It gave one the feeling of lying a-hull. It was only when a particularly large wave approached and took up the slack in the rope that the BUORD brought the bow through the wave....
The only other time that the BUORD brought the bow into the waves was when, after 4 hours, I decided to pull it in. When the line was pulled in so that there was only 50 feet out, then it seemed that the bow wanted to stay pointed upwind. I did not leave it there long enough to test it, so I don't know what the BUORD would do in the long run....
Again it might be asked why the same parachute that pulled the bow of a fin-keeled J-30 into the seas (File S/M-6) would not do the same thing for a Vancouver 27. And again, the answer has to do with the amount of wind, the keel configuration, the rig, and the relative positions of the CLR and CE on the different boats. The J-30 has a small, centrally located fin keel. The Vancouver 27 has a full keel with a cutaway forefoot. The J-30 had sustained winds of 60 knots. The Vancouver had winds of 35 knots.
A larger parachute sea anchor might have made a difference as well. We would like to emphasize that the canopies of these BUORDs are made of coarsely woven mesh material, "the sort of thing you would use to strain plankton out of the sea with" as one sailor described it. Although they have a nominal diameter of about 9 feet, they do not have the holding power of a 9-ft. diameter, zero-porosity sea anchor. Remember, they are designed for dropping torpedoes into the sea and need to have a great deal of "give" built into their canopies.
By coincidence, the Pardeys ran into Anthony Gibb in Australia, and had this to say to Victor Shane in another letter: "Later discussions make us wonder if he had enough wind, or possibly her laying so far off the wind might have been caused by her high bow, the tanks stowed on her foredeck and a very high deck house, combined with a cutaway forefoot."
File S/M-7, obtained from Dennis Lueck, Pensacola FL. - Vessel name Wind Song, hailing port Pensacola, Pilot Cutter designed by Frank Parrish, LOA 32' x LWL 20' x Beam 9' x Draft 5' x 5 Tons - Full keel & cutaway forefoot - Sea anchor: 9-ft. Diameter BUORD on 300' x 1/2" nylon three strand rode with 1/2" galvanized swivel - No trip line - Deployed during passage of frontal trough in shallow water (6 fathoms) off the Florida coast with winds of 35-40 knots and choppy seas of 8 feet - Vessel's bow yawed as much as 90° off to each side in the gusts.
Wind Song, a brand new Pilot Cutter, was being sailed from Tampa to her home port of Pensacola when a weather front arrived. The crew decided to play it safe with the new boat and deployed a 9-ft. BUORD, in 6 fathoms of water, about 30 miles offshore and due west of Bayport, Florida. The parachute did not do a satisfactory job of pulling the bow of Wind Song into the seas. The boat would get beam-on to the seas in the gusts. Notwithstanding, the motion was still much better than lying a-hull. Here is a transcript of her owner's feedback:
After rounding up to deploy the sea anchor, we forgot to return the rudder amidships, so it was hard to port all night (and not discovered till morning). As a result (I believe) the boat would get beam-on to the seas in the gusts and then roll. As it was, the motion was still much better than lying a-hull....
The rode did hit the bobstay and whisker stays quite often but did not chafe. We tried the "Pardey Bridle," but the snatch block stayed against the hull and we were afraid of chafe....
Incidentally, the boat was brand new and we were bringing it home. It had been dead calm and we were motoring north about 50 miles north of St. Petersburg when the front came through. As we had no sailing experience with this boat and it was night, we elected to heave-to with the sea anchor. Today, with similar conditions, we would sail the boat reefed down.
Why didn't the sea anchor pull the bow of this yacht into the seas? The problem of side-to-side yaw is related to the shape of the hull and keel, the position of the CLR (center of lateral resistance), the type of rig and the position of the CE (center of effort). It is most aggravated when the CLR is well aft and the CE well forward. This gives the wind a larger lever to push the bow off.
Boat design has always been the art of compromise and naval architects have seen the cutaway forefoot as something that enhances the course-keeping qualities of a yacht and lessens her tendency to broach in strong following seas. As long as such a yacht is sailing forward her underwater profile resembles an arrow in flight. The trade off, of course, is her behavior at anchor.
More than likely, however, Wind Song just didn't have enough wind. Seraffyn has unevenness associated with her underwater shape as well, but recall the Pardeys' words in File S/M-3, "If there was a lot of wind, the para-anchor held her pretty close to head to wind."
File S/M-6, obtained from Paul C. Brindley, Houston TX. - Vessel name Heaven & Hell, hailing port Houston, J-30 sloop, designed by Rod Johnstone, LOA 30' x LWL 25' x Beam 11' 6" x Draft 6' 6" x 3.75 Tons - Fin keel - Sea anchor: 9-ft. diameter BUORD on 300' x 3/4" nylon three strand rode with no swivel used - No trip line - Deployed during a storm in deep water in the Gulf of Mexico, about 120 miles Southeast of Galveston, with winds of 60 knots and combined seas of about 30' - Vessel's bow yawed about 10° - Drift was .5 -.7 knots during 4 hours at sea anchor.
This is the first file that Victor Shane documented after starting Para-Anchors International in 1981.He comments that it tends to stick in the mind, like that first high school date. It is an important file in other respects as well. The boat, a fin-keeled J-30, rode very well to the 9-ft. BUORD parachute. Up to that time conventional wisdom had it that sea anchors were useless on board so-called "modern fin-keeled sailboats." This was a turning point of sorts.
In a letter to Victor, dated 2 November 1986, Donald J. Jordan, author of widely publicized articles on capsize prevention and inventor of the series drogue wrote the following (reproduced by permission): "Dr. Brindley called and gave me a comprehensive description of his experience.... As you say, the J-30 rode very well in that type of wind and sea. This is the first well-documented instance of a modern sloop riding properly with a sea anchor from the bow."
The 9-ft. diameter BUORD pulled the bow of this yacht into 60-knot winds and 30-ft. seas in a satisfactory way. It kept it there for four hours. However, the crew had inadvertently omitted to use a swivel on the parachute terminal, and the canopy's rotation resulted in a fouled-up useless mess of parachute and kinked-up rode.
After retrieving the mess and stowing it the best they could the crew then used the boat's inboard engine to jog into the seas. Apart from a few near knock-downs, Heaven & Hell emerged from the ordeal intact. From Dr. Brindley's handwritten feedback:
The drogue [meaning sea anchor] worked well. We could have eaten soup below until it twisted shut as we had inadvertently left off the swivel. We made about .5-.7 knots sternway, checked by the Loran. It went to 4-5 knots when the chute twisted shut. I much preferred the bow into the waves.
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.
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.
Using Parachutes, Sea Anchors and Drogues to Cope with Heavy Weather – Over 130 Documented Case Histories