Why Does a Boat Capsize And How to Recover Capsized Boat

Why Does a Boat Capsize And How to Recover Capsized Boat

Capsize is always possible, since the stability of the boat is mostly dependent on the movement of crew weight. Many smaller boats are prone to invert – turn completely upside down – and may do so quickly, so it’s important that you familiarize yourself with the procedure so you can stay calm during a capsize recovery.

The standard way to recover a capsized boat is by using the “Scoop method”, which relies on one person standing on the centerboard to pull the boat upright while the crew is being scooped aboard. For a one person boat, the method is to wrap your arms around the daggerboard and hanging your weight on it to make the boat come slowly upright.

Avoiding a capsize

The easiest way to avoid capsizing is to sail a small keelboat or one of the more stable general-purpose dinghies that are less prone to capsizing than most other dinghies. However, if you do sail a less stable boat, try to sail within the limits of your experience and ability, and to avoid going afloat if the wind is strong. Make sure to know how to reef your boat, while afloat, so that you can adjust sail area to suit the conditions. If reefing is not possible because of the weather, then try to sail as upright as possible by spilling wind from the sails to reduce heeling. Do not make the boat heel and slow down as it will make it more vulnerable to capsizing. Head for the shore quickly, and try to reef the boat ashore. If not possible then move your weight to the high side to try to recover the situation.

sailing and weight

 

Types of capsize

Leeward capsize happens when the wind overpowers the righting effect of the crew’s weight, the boat tips over to leeward, away from the wind, and floods in over the leeward gunwale. Happens mostly when the boat jibes and the crew are not quick enough to move their weight to the new windward side, or when helmsman allows the boat to continue turning, and then is overpowered before he can accelerate on its new course. Once the capsize becomes inevitable, the crew should slip into the water between the boom and the hull. This way you can also avoid inverting a boat, rather than hanging onto the side of the boat trying to avoid getting wet.

Windward capsize is less common and it happens when a dinghy is sailing on a run and it rolls heavily toward the wind. As it rolls, the part of the hull in the water becomes unbalanced and makes the boat turn further away from the wind. The boat continues to roll and then tips over, toward the crew. This type of capsize is much more violent and quicker hence the crew has less time to react.

Capsized boat

Capsize Recovery

The scoop method, relies on one person standing on the centerboard to pull the boat upright. The person should stand to the part nearest to the hull to avoid breaking the centerboard. The scooped person’s weight in the boat helps to prevent it capsizing again once it is righted, and so it should be heavier person that’s righting a boat, leaving the lighter one to be scooped aboard.

Steps of the scoop method capsize recovery:

  1. The crew pushes the centerboard down and then joins the helmsman at the stern. The rudder must be secured in place.
  2. The crew passes the end of the mainsheet over the top of the rudder to the helmsman. This is used as a safety line. Helmsman swims around the bottom of the boat to the centerboard.
  3. The jib sheet is thrown over the boat to the helmsman and the crew then comes inside the hull, with the head toward the bow, holding onto a thwart or toestrap.
  4. The helmsman (or the heaviest person) climbs onto the centerboard and is pulling steadily on the jib sheet.
  5. The boat is coming upright and is scooping up the crew. To help the helmsman get in boat the crew helps him slowly, to avoid another capsize.

 

Single-handed boat method, relies on wrapping your arms around the daggerboard and hanging your weight on it to make the boat come slowly upright.

Steps of single-handed capsize recovery:

  1. As soon as the capsize seems inevitable, climb over the top gunwale to reach the daggerboard.
  2. Step over sidedeck onto daggerboard and hold the gunwale. This way you can pull the boat upright, and climb back in it as it is righted.

Inversion capsize

This is the most difficult one to deal with. It happens when the boat tips over completely upside down during capsize. For dinghies this happens because they usually have built-in buoyancy distributed along the bottom and sides of hull. To recover this boat the water seal must first be broken first, which is difficult to do. The way to recover from inversion is to bring the boat to the capsized position, and then follow the steps from the scoop method.

Steps of inversion capsize recovery:

  1. One person throws the jib sheet across the hull, next to centerboard. The heavier person grabs it and climbs onto the gunwale.
  2. The heavier person pulls the centerboard down and the 2nd person climbs up if the first person couldn’t pull the centerboard down fully. They both stand on gunwale or kneel on the hull, pulling the jib and holding onto centerboard.
  3. The water seal must now be broken and the boat will come up slowly. They keep pulling the jib sheet steadily.
  4. The boat should be on its side now. One person goes around and moves into the boat, floating, preparing to be scooped. And now, the scoop method is used.

Large ship capsize can be quite dangerous, as we can see by the notable capsizings on this wikipedia article. When larger ships such as cargo ships and tankers capsize or sink not only is recovery not possible but great environment damage can occur from spillage of cargo.[8] Larger ships are being equipped with Surfacing System for Ship Recovery which is an inflatable device that is installed in the ballast water tank or within the hull of the vessel and can be deployed within seconds of an accident to stabilize the vessel and give more time for rescue and evacuation.[9]

If the mast is in the mud, in shallow water, it may be too difficult to pull the boat up simply using your body size. In this case you may need to ask for a tow from another helmsman. Attach the tow line to the leeward chainplate or another strong point and pull the boat against the wind. Let the helmsman towing you know that you have your mast in the mud, so he can move slowly until the boat rotates to lie on its side.

Helpful tips:

  • If you get caught under a sail, keep your hand up and create air pocket to breathe. Stay calm, there is no rush, keep paddling keeping your arms up and you’ll find a way out. If there is no air pocket, move quickly to the edge and pull yourself under the gunwale.
  • If the centerboard retracts into its case when inverted, one person should stand on the lip of the gunwale instead of the centerboard and pull the jib sheet. If the air pocket is available under the boat, you can dive below and pull the centerboard out, but only if there is air pocket underneath because it is highly dangerous otherwise.
  • If you fail to recover a capsized boat, climb onto the hull, tie yourself on with the end of a sheet, and wait for rescue. Capsizing can become dangerous quickly if you’re separated from the boat, or trapped underneath it, or even entangled in ropes or rigging. So, sometimes it may be best to sit tight, and wait for rescue.

 

References:

  1.  “SuSy – Surfacing System for Ship Recovery”www.su-sy.eu. Archived from the original on 2017-04-19. Retrieved 2017-01-31.
  2. ^ Munoz, Gabriella. “New Airbags Will Save Ships From Sinking”ScienceAlert. Retrieved 2017-01-31.

 

Credits: 

Pictures: Capsize recovery picture provided by David Merrett

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