Raising a Sunken Vessel

[captnknopf]

I raised a 28 foot wood sail boat with lead keel after a hurricane in about 12 feet of water. I lashed two 55 gallon drums tio long 2x4 boards. The big bung in and the small bung out and at the bottom . I tied the two boards together with enough extra rope that they would sit against the hull on either side of the keel. Let them fill with water, lower and put into position (all done with ropes) and with an air line in each one hooked to a small pump with two valves to keep level, started pumping in air. Each 55 gallon drum will dead lift about 450 pounds. By adjusting the two air lines, it brought the boat up far enough to nail a board over the hole in the side and pump the boat out. This was done with mostly one person and sometimes two.

[lituya1617]

It is pretty easy to raise a sunken 32-footer if the water is shallow, say less than 60 feet. But make sure the vessel will be worth the effort before you start. Sunken boats are worth less than 1/3 their value prior to sinking, sometimes much less than that if there is a structural issue or a lot of damage.
I raised a 40-foot commercial troller in 35 feet of water lin Alaska and it was pretty simple if somewhat time consuming and colder than hell. I just put a bunch of truck inner tubes inside the hull and inflated them with an air hose. The displacement of the hull will determine how many tubes you have to buy. Each tube will inflate to about twenty cubic feet and lift about 1,000 pounds. If the hull weighs 22 tons or 45,000 pounds like the one I worked on, you need about 50 tubes. You will also need a fast compressor and a 200 foot air hose. Each tube takes about 3 minutes to inflate at 35 feet of depth if you have a compressor putting off 150 PSA. Get a lock-on inflation air hose head because it is impossible to hold the tube while you are inflating it. In warm, shallow water, this method works very well and is not too expensive overall. Once you have the decks awash, you will need a good high-volume pump to pump it out so you can tow it ashore. Good luck!

[barnakiel]

If near a hard shore, the vessel can be lifted to the surface with a car mounted crane. Then emptied with fire pumps. Etc.


Offshore a barge mounted crane is at times available.



b.

[captlloyd]

Originally Posted by 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.

Doria dive would be amazing but dangerous. You better know your stuff. A number of divers have died diving on her , odds of surviving a dive on her by amateurs is low.

[a64pilot]

I’m too old and or have lost interest now, but I think I would have been OK.
It’s not the Dive as much as it’s the location, water temp and currents etc.
I think it’s mostly the location, it’s not easy to get to so when people go, they push it harder then they they would if they thought they could come back next week.
The very few time it has been dove by cave divers, they have usually done well. Cave training and wreck penetration go well together. The use of lights, lines, trim and buoyancy control etc.

However I hear it’s not the Dive it once was, she is sinking in the mud and collapsing on her self, just generally deteriorating.

I think there have been about or close to a dozen deaths

[zeehag]

my salvor friend here in mexico uses barrels into which he pumps air via compressor. he also displaces water inside boat with air via compressor. takes time but boat comes back up and cleaning is mandatory. he has raised many sunken boats in this manner

[rpjn59]

Been there done that, it's not always as easy as some say. I raised a bilge keeler that was sunk in the mud. Do to the keels flaring slightly out and the suction from the mud it took twice the displacement of the boat to bust her loose. Then there's the underwater temp repair and god forbid you dont get the gunnels above the water line. Any floatation device that breaks the surface will start to loose it's lifting force. Tubes or bladders that are put into the interior are subject puncture from debris... and again if the interior tubes break the surface the lift stops. The marina electricians who turns off the breaker for a repair and doesn't turn your dock run back on and shuts your pump, resinks the f ing boat to the waterline after its been cleaned and pickled, because the temp patch had a slow leak. Re raise her and the knuckle head neighbor kicks out the plug to your pump and sends back to the waterline, oh-vey...

[jhulmer]

We had to do it on one of my previous boats after Katrina. She sank in about 15ft of water up the river.

I was a scuba instructor and had worked with lift bags also but this required a little more planning.

We decided to use plastic 55 gal barrels rigged in harnesses and 6" straps under the keel.

We plumbed all the barrels with 3/8 poly tubing and led to the support boat (my pontoon boat). Using a scuba tank with an air nozzle after the first stage, we could fill the barrels gradually and equally to balance the lift. Once the gunnels reached the surface we used a Honda powered trash pump to dewater the boat and she floated on her own.

Unlike a lot of my plans this when very well. We completely rebuilt her an sailed her for several more years before I sold her in better shape then I bought her.

[Mr B]

Originally Posted by lituya1617

It is pretty easy to raise a sunken 32-footer if the water is shallow, say less than 60 feet. But make sure the vessel will be worth the effort before you start. Sunken boats are worth less than 1/3 their value prior to sinking, sometimes much less than that if there is a structural issue or a lot of damage.
I raised a 40-foot commercial troller in 35 feet of water lin Alaska and it was pretty simple if somewhat time consuming and colder than hell. I just put a bunch of truck inner tubes inside the hull and inflated them with an air hose. The displacement of the hull will determine how many tubes you have to buy. Each tube will inflate to about twenty cubic feet and lift about 1,000 pounds. If the hull weighs 22 tons or 45,000 pounds like the one I worked on, you need about 50 tubes. You will also need a fast compressor and a 200 foot air hose. Each tube takes about 3 minutes to inflate at 35 feet of depth if you have a compressor putting off 150 PSA. Get a lock-on inflation air hose head because it is impossible to hold the tube while you are inflating it. In warm, shallow water, this method works very well and is not too expensive overall. Once you have the decks awash, you will need a good high-volume pump to pump it out so you can tow it ashore. Good luck!

Thats a great idea and will save me a lot of cash,

I had been looking at inflatable bags to go under my mattresses in my boat purely as a precautionary measure, Or just in case,

Keeping the boat on the surface takes a lot of stress out in an emergency situation,
Being half on the beach when I got wrecked, I still dont know if my boat would sink or not in the open ocean, It does have Flotation chambers in it, But, Hahahaha
I dont want to be in a situation where I need to prove it,

Knowing you cant sink, Gives you time to do any thing that needs doing, Patching holes, Etc Etc,
The truck inner tubes will pack very easy and be out of the way,
six in my 4.5 tons is a bit of overkill, But four near the transom will keep the motor out of the water high and dry, Tied low down on the sugar scoops,

Having been sunk, Half submerged, The batterys were the first to go as they were in the bottom of the hulls, They shorted out as the water came in, No power,
I have now moved the batterys up to the deck level, Ensuring I have power above the water level,

With a storm coming and a vacated boat, It would be a good idea to inflate the tubes before leaving the boat,
That way the boat cant sink even with holes in it from the storm,

Thanks, Brian,