UKSteve

A few issues to consider:

1: Consider working shallow (lift bags) with lines to wreck... much easier to manage when breaking free from bottom. Initial lift clears bottom. Then you can progressively lift the wreck lifting bags stay in shallow water. This keeps required free air volumes low. It also limits how far things could run away from you. If your initial lift starts with the bags at 5m depth then they can only go 5m uncontrolled. One clear of the bottom you use two sets of bags..leapfrogging them down the lines to bringthe boat into shallower water. Once there you might want to bring it close to shore and settle it on the bottom before doing the final lift with bags attached to the boat itself.

2. Don't underestimate the "suction" effect of the boat on bottom. Can almost double the initial lifting capacity required. A number of small bags is a lot safer than one large bag. Once filled to capacity, a small bag will not generate any more lift if it suddenly rises. Try to have as many bags as possible full then one as the variable lift...helps control the lift more easily.

3. Keep any work conducted at depth as simple as possible. Do the tricky stuff shallow. Only tie knots etc in the water where it is not possible to prepare lines etc on surface. Only use knots where you cant use a shackle.

4. Severely limit number of people in the water during actual lifts - and ideally dont have anyone in the water. With lifting bags shallow you can run hoses to them from surface rather than have someone in the water. Safest place when lifting is on a boat nearby.

5. Final bit is tricky - when the boat is nearly at surface and awash. Probably best to use tide to get it close to shore on a high tide then get it out on a low tide. And consider where you are going to put it!!

Good luck and have fun.

Steve