Turtling (sailing)

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Boat that has turned turtle
(upside down)

In dinghy sailing, a boat is said to be turtling or to turn turtle when the boat is fully inverted with the mast pointing down to the lake bottom or seabed.[1][2] The name stems from the appearance of the upside-down boat, similar to the shell of a sea turtle. The term can be applied to any vessel; turning turtle is less frequent but more dangerous on ships than on smaller boats. Relative to monohulls, it is more hazardous on multihulls, because of their inherent stability in an inverted position. Measures can be taken to prevent a capsize from becoming a turtle.[3][4][5][6]

Definition and prevention

Righting a capsized Hobie Cat.
Practice righting a capsized dinghy

Prevention is the first priority.[4][5] [upper-alpha 1]

Capsizing (but not necessarily turtling) is an inherent part of dinghy sailing, and is considered to be "routine." It is not a question of "if" but a question of "when."[6][7][8] Practice capsize drills are (and should be) part of the training of every dinghy sailor.[5][6]

For those who do not want the experience, a keelboat monohull has physics on its side.[7][9] See Limit of Positive Stability. But even yachts can capsize and turtle in extraordinary conditions, so design considerations and suitability for particular tasks, locations, weather, duration and situations are essential queries.[7][8][9][10][11][12][13] "Such events can overcome skill and experience"; boats need to be appropriate for foreseeable conditions.[8][9][10][11][13][14] It is a fundamental question of seaworthiness.

Turtling commonly occurs when a boat capsizes and is not righted or attended to in time, allowing it to roll through the approximately 90 degrees of a capsize through to 180 degrees from upright.[4][5]

Prevention and delay of turtling in dinghies is the highest priority turtling can be catastrophic in consequences but it depends on skill, ability and athleticism, which vary greatly.[6] As John Rousmaniere wrote: Testing confirms the Royal Yachting Association's conclusion that "a decisive way to address entrapment is to immediately right the boat by putting weight on the centerboard" daggerboard, (or bilgeboard in a Scow).[4] This should be adopted by US Sailing and other organizations "as doctrine."[4] Thus, reliance on boat handling and seamanship may be misplaced.[4]

Sealing masts and attaching flotation are effective preventatives for turtling of dinghys, but not widely utilized.[4][5] More certain preventatives for this includes various forms of flotation added to the tip of the mast or top of the mainsail.[upper-alpha 2] These include floats (e.g., one that looks like a streamlined blimp used on Hobie 16s)[upper-alpha 3][15] or a "sail patch" a sleeve with built in flotation that fits over the top of the sail, available for example as option on the Wayfarer (dinghy) Mark IV.[6] Another alternative is to seal the mast, thereby increasing its buoyancy.[15]

As an emergency palliative, putting flotation (i.e., a spare life vest or other personal flotation device), onto the end of the mast straight away after a capsize and without delay, can forestall a turtle. Conversely, climbing onto the side of a knocked down boat can increase the likelihood of turtling, as it moves weight higher over the center of gravity, may also increase windage, and thus can effectively drive the mast downward.[5]

Several devices have been patented to prevent turtling.[16][17] Capsizing is particularly troublesome for catamarans and trimarans, which are especially hard to right.[4][16]

The use of a trapeze, harness, Jackline or other tether can cause injury or death due to entrapment if a boat turtles.[4][11][14][18][19]

Practice and cure

Righting a turtled dinghy is one of the most difficult maneuvers. Recovery in a monohull requires releasing the main sheet and jib sheet, lowering the spinnaker if it is deployed, standing on the bottom of the boat and levering on the centerboard, or standing on the centerboard (there may be weight and placement restrictions). It is important that other members of the crew not be on top the boat, as this can drastically increase resistance to righting the craft.[5] The use of "righting ropes" materially aids the process. Standing on the centerboard and "piggybacking" of crew members can be highly effective to right a turtled dinghy, as it increases both the weight and leverage being applied. Use of powerboats to aid is problematical, and depending on the technique used there are several may or may not succeed.[4] See Capsize.[20]

Multihulls

Multihull Aleph capsizing during America's Cup trials, Plymouth

In yacht sailing, multihulls are deemed to be more prone to turtling than keeled monohulls, and there is essentially no way to right them if they overturn. The juxtaposition of the hulls and sail when turtled it makes them inherently stable when inverted makes them especially resistant to righting.[4][16] Consequently, some larger multihulls are built with a turtle emergency escape hatch beneath the hull. Indeed, some locales require such safety hatches.[21] There are, however, those who feel that the likelihood of a capsize of a large multihull is overrated.[22][23] There are others who state that a self-righting multihull is the answer, along with designing in safety and proper operation.[21] A patent has been issued specifically concerning righting of turtled large multihulls.[24] It is intended to avoid the necessity to use divers and special equipment in a recovery.[24]

It is, however, possible (and often successfully) to right a capsized small multihull, e.g., a Beachcat and Hobie 16. The process begins with positioning ropes so that the crew can get leverage (acting together is key). Righting Beach catamarans that are turtled can be extremely difficult. Loss of sails, rigging, masts and boats can occur.[20] Not to mention sailors.[6][18] A singled-handed self rescue can be assisted by filling a garbage bag (called in this context a "righting bag") with water, and throwing it over the rescuer's shoulder.[20] See Hobie 16 which suggests sitting on the rear of one sponson, which will upturn a turtled Hobie.

Even some large multihulls can be righted at sea it is a long shot provided that the skipper is well prepared, knows what he is doing, and has appropriate devices, tools, skills, a workable plan, cooperative waves, weather and wind, and some luck.[21][22]

Notable events

The Fastnet race, and particularly the 1979 Fastnet race (the disastrous race that changed yacht racing for all time),[12][25][26] has been the occasion for many sailboat capsizes, turtlings and fatalities.[12][13] In the 1979 race, "15 sailors died, five boats sank, and at least 75 boats flipped upside down."[12] In any event, adopting heaving to as a storm tactic proved to be a good preventive of capsize during the race. Not one of the hove to yachts were capsized or suffered any serious damage.[27] See also Capsize of Drum (1985) and Capsize of Rambler (2011),[8] both of which involved large Maxi yachts that lost their keels.

In one notable crash, the high speed experimental sailing hydrofoil trimaran Hydroptère set a world speed record, then pitchpoled while going over 60 knots, The turtled yacht had to be towed back to port for being turned right side up.[28]

On 13 June 2012, in the trials leading to the America's Cup, Oracle Team USA on an AC45 spectacularly capsized the boat. and it was righted with minimal damage ("there's a little rip there") ten minutes later. Skipper Russell Coutts dismissed it as "a learning experience." This was an epilogue to earlier similar incidents by other teams in Australia.[29][30]

On 9 May 2013, the 2013 America's Cup challenger Artemis broke apart, broached. capsized, and turtled destroying its wing/sail and trapping two crew members under its hull. The AC72 wing-sail catamaran was sailed on behalf of the Royal Swedish Yacht Club (KSSS), sponsoring Team Artemis. Andrew "Bart" Simpson, an Olympic-gold-medal winning British sailor, died as a result.[31][32]

In the 2011 Chicago to Mackinac Boat Race the high performance monohull Sportsyacht Kiwi 35 WingNuts turtled in an extreme storm, killing the captain and one crew member. Later inquiry said that the boat specifically its high performance extremely wide low displacement hull[14][19][33] was unfit for the location, weather and the multiday and lengthy race, and urged race officials to change ratings and revoke privileges to enter the race.[8][10][11][19] [upper-alpha 4] The waves were not all that unusual, although the wind was. The boat may have buried one of its hiking wings into a wave, causing it to 'trip,' and had the other lifted by the wind.[33] It is rare but not unheard of for keelboats to turtle and remain upside down, particularly if its keel is intact. However, this boat's unique hull form, which made it very fast, also rendered it more stable upside down than right side up. This was a recipe for the disaster.[14][33] This loss was occasioned despite a competent and experienced crew which was as well equipped and prepared as thought to be necessary.[8][10][11][14][33] WingNuts met then current offshore stability standards, which failed to adequately take into account the dynamic effect of the "radical" winged hull.[8][10][19][33] [upper-alpha 5]

Legal implications

Capsize and turtling can result in legal liability for damages due to negligence.[18]

See also

References

Footnotes

  1. "A seaman laboring under an undue sense of security becomes at once worth hardly half his salt." Joseph Conrad. Conrad, Joseph. The Mirror of the Sea. p. 18. Retrieved 21 November 2013.  cited in Rousmaniere at p. 19.
  2. Intended for "rough weather or novice racers." "Hartley Wayfarer Mark IV". Retrieved 13 November 2013.  Distances, obstacles and the likelihood of rescue are other factors that should be considered in deciding whether to prepare for the worst. As Franz Kafka, Larry McMurtry in Lonesome Dove, and Huey Lewis and the News have written: "It is better to have it and not need it, than need it and not have it."
  3. "Easily removed for trailering or racing." "Hobie Mast Float – Mama Bob". Sailboat Marine. Retrieved 17 November 2013. 
  4. On the other hand, one meteorologist suggested:
    "Veteran Chicago-Mac racers have encountered similar conditions during previous races and understand that coping with severe weather is part of the challenge. Skippers must prepare their boats, train their crew, maintain a watchful eye for approaching storms and "the dearest friend (and most menacing foe) of all sailors -- the wind."
    Thornton, Mark A. (August 2011). "2011 Chicago-Mackinac Race: A Meteorological Summary". Retrieved 6 December 2013. 
  5. "On paper, WingNuts met all stability requirements for the Chicago-Mac race. The race required that all boats have an Offshore Racing Rule (ORR) handicap measurement certificate, a document that includes two measures of stability: Limit of Positive Stability (LPS) and the Stability Index (SI). However, after the accident, the US Sailing panel found that the ORR formulas did not adequately penalize the Kiwi 35’s extreme flare, the difference between the waterline beam and the maximum beam. When the panel eliminated a fixed lower limit for the “capsize increment” one of the factors used in the calculating stability index WingNuts’ index of 100.7 plummeted to 74.4. No other boat in the race had the same drastic reduction in its stability index when the same math was applied. In addition, the panel noted that the Right Arm Curve (GZ Curve)—a graphic representation of the boat’s stability—revealed WingNuts to be just as stable inverted as it was right side up, sharply reducing any chance of recovery from a full capsize." "PS Analysis: The 2011 WingNuts Capsize Practical Sailor". Practical Sailor. April 2012 Issue. Retrieved 6 December 2013. 

Endnotes

  1. "turtle, turn turtle (of a boat) to turn over completely while sailing". Oxford Advanced Learner's Dictionary. Oxford University Press. 2013. Retrieved 3 December 2013. 
  2. "Definition of turtle in English "turn turtle" (chiefly of a boat) turn upside down: ". Oxford Dictionaries. Oxford University Press. 2013. Retrieved 3 December 2013. 
  3. George 1971, p. 82-9.
  4. 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10 Rousmaniere, John. "Tests of Sailor Retrieval, Capsize Recovery and Entrapment" (PDF). US Sailing. Retrieved 19 November 2013. 
  5. 5.0 5.1 5.2 5.3 5.4 5.5 5.6 "Fusion Capsize Manual" (PDF). F-15 dinghy. Retrieved 18 November 2013. 
  6. 6.0 6.1 6.2 6.3 6.4 6.5 Rousmaniere, John (22 October 2011). "Youth sailing 420 tragedy on Severn River report - Organizations" (PDF). US Sailing. Retrieved 27 November 2013. 
  7. 7.0 7.1 7.2 "Will I capsize?". Discover Boating. Retrieved 22 November 2013. 
  8. 8.0 8.1 8.2 8.3 8.4 8.5 8.6 Rousmaniere, John (13 September 2012). "Sailing Accidents: Lessons Learned". Sail Magazine. Retrieved 27 November 2013. 
  9. 9.0 9.1 9.2 Dashew, Steve (8 January 2012). "Evaluating Stability and Capsize Risks for Yachts". setsail.com. Retrieved 22 November 2013. 
  10. 10.0 10.1 10.2 10.3 10.4 Keilman, John (30 October 2011). "Report: Boat in deadly accident unfit for Mackinac race — Craft that capsized called too unstable for long competition in area prone to severe weather". Chicago Tribune. Retrieved 22 November 2013. 
  11. 11.0 11.1 11.2 11.3 11.4 Hawley, Chuck; Rousmaniere, John; Naranjo, Ralph; McCurdy, Shiela (18 October 2011). "Inquiry Into the Chicago yacht Club-Race to Mackinac Capsize and Fatalities" (PDF). US Sailing. Retrieved 23 November 2011. 
  12. 12.0 12.1 12.2 12.3 Rousmaniere, John (January 2000). "Revisiting Lessons from the Fastnet". SailNet.com. Retrieved 25 November 2013. 
  13. 13.0 13.1 13.2 Forbes, Sir Hugh; Laing, Sir Maurice; Myatt, Lt. Col. James (1979). "1979 Fastnet Race Inquiry" (PDF). Royal Yachting Association, Royal Ocean Racing Club. Retrieved 23 November 2013. 
  14. 14.0 14.1 14.2 14.3 14.4 "PS Analysis: The 2011 WingNuts Capsize Practical Sailor". Practical Sailor. April 2012 Issue. Retrieved 6 December 2013. 
  15. 15.0 15.1 "What Should I do to Prevent Turtling". sailingforums.com. Retrieved 16 November 2013. 
  16. 16.0 16.1 16.2 "U.S. Patent No. 5255624". Google patents. Retrieved 17 November 2013.  which includes a discussion of turtling.
  17. US 5255624, Legare, David J., "Sailboat mast flotation device", published 26 October 1993, issued 26 October 1993 
  18. 18.0 18.1 18.2 Dolan, Andy (17 January 2012). "Girl, 11, 'drowned after freak gust of wind capsized catamaran, trapping her underwater in harness'". Daily Mail. Retrieved 21 November 20123. 
  19. 19.0 19.1 19.2 19.3 Landry, Chris (31 January 2012). "Boat in fatal capsize was 'inappropriate' for race". Soundings. Retrieved 7 December 2013. 
  20. 20.0 20.1 20.2 "Righting a Turtled Hobie cat". Retrieved 21 November 2013. 
  21. 21.0 21.1 21.2 Kelsall, Derek. "Catamaran Seaworthiness and Safety" (PDF). Kellsall Catamarans. Retrieved 19 November 2013. 
  22. 22.0 22.1 Farrier, Ian. "Multihull Safety". Farrier Marine. Retrieved 19 November 2013. 
  23. Triton, Robb Kane; Triton, Ann Marie Powers (30 May 2005). "Don't buy a Catamaran, you'll die!!". Triton Boat Works. Retrieved 20 November 2013. 
  24. 24.0 24.1 Lake, John A. "Patent 465166 Description, Multi-hull sailboat righter". Retrieved 20 November 2013. 
  25. Rousmaniere, John (1980). Fastnet, Force 10: The Deadliest Storm in the History of Modern Sailing (Paperback). New York: W. W. Norton & Company (17 April 2000). p. 304. ISBN 0393308650.  ISBN 978-0393308655
  26. "Fastnet 79: The Disaster that Changed Sailing (Eye witness accounts)". Yachting World. Retrieved 24 November 2013. 
  27. Pardey, Lin (2008). Storm Tactics Handbook, 3rd Ed., Modern methods of heaving-to for survival in extreme conditions. Arcata, California: Pardey Books. p. 97. ISBN 978-1-92921-447-1. 
  28. "Hydroptère: 61 knots and huge crash with 35-38 knots, gusts over 45". Fos-sur-Mer: Catamaran Racing. 22 December 2008. Retrieved 10 November 2013. 
  29. "America's Cup: Russell Coutts on AC45 Oracle capsizes spectacularly in San Francisco" (video). Sailing News. Retrieved 19 November 2013. 
  30. Gladwell, Richard. "America's Cup: Coutts capsizes in San Francisco - crew injured" (Video). Sail-World.com. Retrieved 19 November 2013. 
  31. Elias, Paul; Wilson, Bernie (9 May 2013). "America's Cup Sailor Dies In Boat Capsize". Huffington Post (San Francisco). Retrieved 19 November 2013. 
  32. "America's Cup Boat Capsizes, Leaving 1 Dead" (video). ABC News. 9 May 2013. Retrieved 19 November 2013. 
  33. 33.0 33.1 33.2 33.3 33.4 Sharp, Eric (21 July 2011). "Kiwi 35 'probably as stable upside down as she was upright'". Detroit Free Press (SailWorld.com). Retrieved 6 December 2013.  including a picture of the turtled WingNuts

Sources

  • Colgate, Stephen (1978). Fundamentals of Sailing, Cruising, & Racing. New York: W.W. Norton & Company. pp. 97–100. ISBN 0-393-03811-4. 

Further reading

External links

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