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, riverbed, or seabed.[1][2] The name stems from the appearance of the upside-down boat, similar to the carapace (top shell) of a sea turtle.[3][upper-alpha 1][upper-alpha 2] The term can be applied to any vessel; turning turtle is less frequent but more dangerous on ships than on smaller boats.[upper-alpha 3][4] It is rarer but more hazardous for multihulls than for monohulls, because of multihulls are harder to flip in both directions. Measures can be taken to prevent a capsize (where the boat is knocked over on its beam-ends but not yet inverted) from becoming a turtle (with bottom up).[5][6][7][8]
When a boat is "turned over completely" it has turned turtle.[1][2][3][9] Some sources treat the term "turtle" as synonymous with "capsize" or "keel over".[4][10] but most others make a distinction.[upper-alpha 4] Carrying too much sail or loss of control can lead to broaching—the boat heels too far to one side, or capsizes.[11] While all turtlings involve a capsize, the converse is untrue. Prevention is the first priority.[6][7][upper-alpha 5]
With the exception of self-righting watercraft, vessels have an angle of vanishing stability (AVS). External forces aside, if they are tilted at an angle less than the AVS, they will pop back upright. If they are tilted at an angle greater than the AVS, they will turn turtle and stay there. In other words, non-self-righting vessels are stable when turtled. Their primary stability and secondary stability are greater than zero, tending to right them, but their tertiary or inverted stability is less than zero, and tends to keep them upside-down.[12]
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".[8][13][14]
For those who prefer to avoid the experience, a keelboatmonohull has physics on its side.[13][15] (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.[13][14][15][16][17][18][19][20] "Such events can overcome skill and experience"; boats need to be appropriate for foreseeable conditions.[14][15][16][17][19][21] 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.[6][7]
Prevention and delay of turtling in dinghies is the highest priority[20]—turtling can be catastrophic in consequences—but it depends on skill, ability and athleticism, which vary greatly.[8][20] 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).[6] His 2012 report advises that "US Sailing and other organizations should consider establishing this as doctrine." Thus, reliance on boat handling and seamanship may be misplaced.[6]
A Hobie catamaran with a masthead float to prevent turtling
Sealing masts and attaching flotation are effective preventatives for turtling of dinghies, but not widely utilized.[6][7] More certain preventatives for this includes various forms of flotation added to the tip of the mast or top of the mainsail.[upper-alpha 6] These include floats (e.g., one that looks like a streamlined blimp used on Hobie 16s)[upper-alpha 7][22] 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.[8][20] Another alternative is to seal the mast, thereby increasing its buoyancy.[22]
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.[7]
Several devices have been patented to prevent turtling.[23][24] Capsizing is particularly troublesome for catamarans and trimarans, which are especially hard to right.[6][23]
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.[7] 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.[6] See Capsize.[26] Rigging righting lines depends upon proper placement, and critically should be done in advance of the need to use them.[20][27]
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.[6][23] Consequently, some larger multihulls are built with a turtle emergency escape hatch beneath the hull. Indeed, some locales require such safety hatches.[28] There are, however, those who feel that the likelihood of a capsize of a large multihull is overrated.[29][30] There are others who state that a self-righting multihull is the answer, along with designing in safety and proper operation.[28] A patent has been issued specifically concerning righting of turtled large multihulls.[31] It is intended to avoid the necessity to use divers and special equipment in a recovery.[31]
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,[26] not to mention sailors.[8] 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.[26] 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 they are doing, and has appropriate devices, tools, skills, a workable plan, cooperative waves, weather and wind, and some luck.[28][29]
In December 2008, the high speed experimental sailing hydrofoiltrimaranHydroptère 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.[35]
In the 2011 Chicago Yacht Club Race to Mackinac, the high performance monohull sportsyachtWingNuts, a Kiwi 35, turtled in an extreme storm, killing the captain and one crew member. Later inquiry determined the boat—specifically its high performance extremely wide low displacement hull[21][25][36]—was unfit for the location, weather, and the lengthy multiday race format, and urged race officials to change ratings and revoke privileges for similar boats to enter the race.[14][16][17][25][upper-alpha 9] 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.[36] 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.[21][36] This loss was occasioned despite a competent and experienced crew which was as well equipped and prepared as thought to be necessary.[14][16][17][21][36]WingNuts met then current offshore stability standards, which failed to adequately take into account the dynamic effect of the "radical" winged hull.[14][16][25][36][upper-alpha 10]
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.[37][38]
A sailboat or sailing boat is a boat propelled partly or entirely by sails and is smaller than a sailing ship. Distinctions in what constitutes a sailing boat and ship vary by region and maritime culture.
A catamaran is a watercraft with two parallel hulls of equal size. The distance between a catamaran's hulls imparts resistance to rolling and overturning. Catamarans typically have less hull volume, smaller displacement, and shallower draft (draught) than monohulls of comparable length. The two hulls combined also often have a smaller hydrodynamic resistance than comparable monohulls, requiring less propulsive power from either sails or motors. The catamaran's wider stance on the water can reduce both heeling and wave-induced motion, as compared with a monohull, and can give reduced wakes.
A daggerboard is a retractable centreboard used by various sailing craft. While other types of centreboard may pivot to retract, a daggerboard slides in a casing. The shape of the daggerboard converts the forward motion into a windward lift, countering the leeward push of the sail. The theoretical centre of lateral resistance is on the trailing edge of the daggerboard.
The Fastnet Race is a biennial offshore yacht race organized by the Royal Ocean Racing Club (RORC) of the United Kingdom with the assistance of the Royal Yacht Squadron in Cowes and the City of Cherbourg in France.
The Chicago Yacht Club Race to Mackinac is a 333-mile annual yacht race starting in Lake Michigan off Chicago, Illinois, and ending in Lake Huron off Mackinac Island, Michigan. It is hosted and managed by the Chicago Yacht Club. The "Mac" was first run in 1898 and is the oldest annual freshwater distance race in the world. The race hosts several hundred competitors each year and over 3,000 sailors.
A Bermuda rig, Bermudian rig, or Marconi rig is a configuration of mast and rigging for a type of sailboat and is the typical configuration for most modern sailboats. This configuration was developed in Bermuda in the 1600s; the term Marconi, a reference to the inventor of the radio, Guglielmo Marconi, became associated with this configuration in the early 1900s because the wires that stabilize the mast of a Bermuda rig reminded observers of the wires on early radio masts.
Capsizing or keeling over occurs when a boat or ship is rolled on its side or further by wave action, instability or wind force beyond the angle of positive static stability or it is upside down in the water. The act of recovering a vessel from a capsize is called righting. Capsize may result from broaching, knockdown, loss of stability due to cargo shifting or flooding, or in high speed boats, from turning too fast.
In sailing, a boom is a spar (pole), along the foot of a fore and aft rigged sail, that greatly improves control of the angle and shape of the sail. The primary action of the boom is to keep the foot flatter when the sail angle is away from the centerline of the boat. The boom also serves as an attachment point for more sophisticated control lines. Because of the improved sail control it is rare to find a non-headsail without a boom, but lateen sails, for instance, are loose-footed. In some modern applications, the sail is rolled up into the boom for storage or reefing.
In sailing, hiking is the action of moving the crew's body weight as far to windward (upwind) as possible, in order to decrease the extent the boat heels. By moving the crew's weight to windward, the moment of that force around the boat's center of buoyancy is increased. This opposes the heeling movement of the wind pushing sideways against the boat's sails. It is usually done by leaning over the edge of the boat as it heels. Some boats are fitted with equipment such as hiking straps and trapezes to make hiking more effective.
Hobie Cat is a company that manufactures sailing catamarans, surfboards, sailboats, kayaks, stand-up paddle boards, and pedalboards as the Hobie Cat Company. It was founded in 1961 by Hobart Alter, who originally manufactured surfboards. Its line of products has included more than twenty sailing craft, plus a variety of other watercraft.
The International Offshore Rule (IOR) was a measurement rule for racing sailboats. The IOR evolved from the Cruising Club of America (CCA) rule for racer/cruisers and the Royal Ocean Racing Club (RORC) rule.
A sailing hydrofoil, hydrofoil sailboat, or hydrosail is a sailboat with wing-like foils mounted under the hull. As the craft increases its speed the hydrofoils lift the hull up and out of the water, greatly reducing wetted area, resulting in decreased drag and increased speed. A sailing hydrofoil can achieve speeds exceeding double and in some cases triple the wind speed.
In sailing, the limit of positive stability (LPS) or angle of vanishing stability (AVS) is the angle from the vertical at which a boat will no longer stay upright but will capsize, becoming inverted, or turtled.
The term sportsboat first appeared in the late 1980s and early 1990s to describe trailer sailers that were optimised for high performance at the expense of accommodation and ballast. The very definition of the term "sportsboat" is evolving.
John Rousmaniere is an American writer and author of 30 historical. technical, and instructional books on sailing, yachting history, New York history, business history, and the histories of clubs, businesses, and other organizations. An authority on seamanship and boating safety, he has conducted tests of equipment and sailing skills and led or participated in fact-finding inquiries into boating accidents. He has been presented with several awards for his writing and his contributions to boating safety and seamanship.
The following outline is provided as an overview of and topical guide to sailing:
The Hobie Bravo is an American catamaran sailing dinghy that was designed by Hobie Cat in 2000 and first built in 2001. The design is intended for sailing from beaches by one or two people.
The Hobie 14 is an American catamaran sailing dinghy that was designed by Hobie Alter and first built in 1967.
The Nacra 5.2 is an American catamaran sailing dinghy that was designed by Tom Roland as a one-design racer and first built in 1975. Other than the small production run Nacra 36, the Nacra 5.2 was the first Nacra brand boat and established its reputation.
↑ A related nautical turtle metaphor is the term Turtleback Deck or "deck, turtle nautical: A term applied to a weather deck that is rounded over from the shell of the ship so that it has a shape similar to the back of a turtle. Used on ships of the whaleback type and on the forward weather deck of torpedo boats." "World War II Naval Dictionary". USS Abbot (DD-629). Archived from the original on 12 December 2013. Retrieved 19 February 2014.
↑ In larger vessels a capsize almost inevitably leads to a sinking. "To turn upside down, and usually, to sink. There is no vessel so large that the largest ocean wave, taken broadside, cannot capsize." "Naval Slang Dictionary"(PDF). p.6. Archived from the original(PDF) on 2 November 2013. Retrieved 19 February 2014.
↑ "A seaman laboring under an undue sense of security becomes at once worth hardly half his salt." –Joseph Conrad. Conrad, Joseph (1921). The Mirror of the Sea. Doubleday, Page. p.18. cited in Rousmaniere at p. 19.
↑ 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."
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.
↑ "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. Retrieved 6 December 2013.
↑ Pardey, Lin (2008). Storm Tactics Handbook, 3rd Ed., Modern methods of heaving-to for survival in extreme conditions. Arcata, California: Pardey Books. p.97. ISBN978-1-92921-447-1.
This page is based on this Wikipedia article Text is available under the CC BY-SA 4.0 license; additional terms may apply. Images, videos and audio are available under their respective licenses.
