Raising a Sunken Vessel

[chrismct]

In light of recent weather events in NC and the likely possibility of my 32' Columbia visiting Davy Jones......has anyone ever raised a sunken boat. How hard is it? Can you do it without another vessel? I am a Divemaster and have done classes on recovery operations.....just not on a boat.

[Pete7]

Not a boat but a large ships anchor. Needed lots of hands to help, lifting bags which we had in the club and spare cylinders to inflate them with. The tricky bit with a yacht will be getting the lifting bags low enough so that the deck is above the waterline when its lifted so you can then bail the rest of the boat out.

However, lets look on the bright side first and hope for the best.

Pete

[a64pilot]

Lift bag in the saloon, pump air until she floats, then a trash pump to dry her out, assuming of course not deep water.

[chrismct]

WOOOHOOOO my girl made it.....shes on the dock but upright

[belizesailor]

Originally Posted by a64pilot

Lift bag in the saloon, pump air until she floats, then a trash pump to dry her out, assuming of course not deep water.

....to expand...its a relatively easy process if the boat is not badly holed. You only need enough lift to get deck flush with water surface...then a big ass trash pump does the rest. Any significant breaches in hull will need to be plugged before pumping. A big trash pump can overcome small ones...like a failed thru hull/hose for example.

Ive also seen it done in a slip, where most sinkings occur, with a few come alongs attached to dock on either side.

[Dayo]

Captain Fatty did ig with old life vests. Just takes ! little ingenuity.

[ShellBack89]

Originally Posted by chrismct

WOOOHOOOO my girl made it.....shes on the dock but upright

Great news!

[Pete7]

The problem with using the lifting bags inside is you are asking a diver to go inside. Visibility will be nil after a storm, cushions and stuff will be floating around and you are asking that he find the floor supports and tie lifting bags to them in zero vis?

This won't be nice blue water diving and does carry some risk even when very shallow water. You will want experienced wreck divers who are used to confined spaces rather than someone with a PADI certificate gained on a holiday.

Pete

[a64pilot]

Yes, but I’m full cave trained both PSAI and NSS-CDS. Full cave divers are not a rare thing anymore, it’s almost mainstream diving now.

Goal was the Andrea Doria, but I got into this cruising thing, and money and time evaporated. Now I’m likely too old.
Plus I’m thinking Boat at or near dock, getting fuel all over you would probably be the worst of it.
Then there is of course once you raise it, it’s off to the disposal yard almost certainly, but maybe by raising it yourself you can avoid a huge financial liability?

I wouldn’t want a boat that had been sunk myself, salt water would get into all kinds of places you wouldn’t want it, even though I have seen at least one sunk IP resurrected.

[zengirl]

Originally Posted by chrismct

WOOOHOOOO my girl made it.....shes on the dock but upright

So happy for you! Yippee!

[Pete7]

Originally Posted by a64pilot

I wouldn’t want a boat that had been sunk myself, salt water would get into all kinds of places you wouldn’t want it, even though I have seen at least one sunk IP resurrected.

Especially if it had a composting head

Your right, oil, diesel in addition to the saltwater is going to make a right mess.

Pete

[freedom 32]

'Nothing pretty about a raised boat. I and a number of my slip neighbors had the experience last year with Hurricane Irma. Something you might encounter (if it's your boat) is a considerable amount of emotionality.

My response was to pretty much just walk away from the salvage boat. Since then, I have regretted not picking the dead boat for usable and sentimental items: helm, winches, bright work?

This will take some time and effort, regardless of whether you do it yourself, or pay someone to. Insurance Companies and Salvages can be quite an experience. Good luck

[seabreez]

Originally Posted by chrismct

In light of recent weather events in NC and the likely possibility of my 32' Columbia visiting Davy Jones......has anyone ever raised a sunken boat. How hard is it? Can you do it without another vessel? I am a Divemaster and have done classes on recovery operations.....just not on a boat.

I have raised many boats from sailboats and power from 26 feet to 72 feet. The system was not complicated. we used inner tubes from trucks and farm tractors. We had a truck plastic air line on each inner tube with different lengths, deflate the inner tube dry dry dry and separate them inside the boat at strategic place. before you do all that drop a suction hose at the lowest point in the boat. Then you start inflating each one with some air and wait for a reaction. do not overfill as when they reach the surface the tube will explode. When you lift to the surface start the water trash pump and it will lift out on its own. 26 foot will take 4 tubes, 32 will take 6 the 72 took 10 tubes. We even lifted a 55 foot tub boat with 10 tubes.

[Lepke]

I did salvage as part of my yard business. Lift bags are the easiest way. I believe there are places to rent them. Keep in mind the bags will support the weight of the vessel, hull engine everything. The bags will be pushing against whatever is above them. Without care in planning, cabinets will be crushed, hatches forced open and so on. In wood boats, the cabin top is rarely strong enough to carry the weight. Most monohulls are 2 piece. To many bags and to much pressure can separate the 2 parts. The hull has to float high enough so it can be pumped out. Whatever caused the sinking needs to be patched before installing the bags and raising. Sometimes additional bags or pontoons are placed along side with straps underneath before applying air.

[Mike Banks]

I can not see any way it can be done without the use of another vessel however small, if only to transport the gear needed.

My advice would be to hire a motor vessel, compressor, inflation bags, pump, ropes, webbing lifting slings and shackles etc and your dive equipment. After a storm the water is likely to be murky, so if you get good underwater visibility you will be fortunate.

You know how it goes from there. Once your vessel is sub-surface and the lifting bags visible, tow it to a nearby beach, prop up the hull by tying both vessels together bow and stern, then as soon as the tide drops sufficiently, pump out the sunken vessel.

If there are holes, you will have to fix them first. I use 3 mm and 4 mm plywood sheets epoxy saturated, and with slats of wood about 50 mm x 30 mm epoxy glued thin end down and screwed from beneath at about four inch centres so that it resembles a wash board, flexible but only in one direction. These patching panels can be quickly cut to size and placed over quite large holes. The bigger the hole, the heavier one has to make the panel. 15 mm plywood with 150 mm x 100 mm battens at 200mm centres will hold quite a lot of water--sufficient to allow most vessels to float as long as the hole is not absurdly large. Most of the curvature of the hull is athwartships, and the bedding compound takes up the curvature fore and aft quite well.

Since these are just to get you to a slip, any rubberised bedding compound will effect a seal as long as the panel is screwed firmly to the hull or through bolted in the event of a larger hole. Blu-tak will serve if nothing better is available, and can be bought at any paper-shop or office supplies. As water is pumped out, water pressure will hold the patch firmly in place until you can get the boat to a travel-lift..

For most vessels having only a couple of metres draught, 4 mm ply will patch most holes up to about a quarter of a metre across. Bearing in mind that several of these panels can be made from one sheet of 4 mm plywood and with birch or any strong light timber as uni-directional stiffening battens, they can be stored aboard interleaved under a coach-house roof, on under a bed. Of course no one intends to ground on rocks or a reef--but it would be nice to have a way of saving the vessel aboard--and you can sleep on it and keep your U-rite or Blu-Tak in a locker..