Gareth
The Wessex Archaeology site has a great deal of information relating to wrecks recovered from the sea. Unless someone beats me to it I will try to find a link and post later.
I dont say it has a great deal advise however the acciant wooden boat recovered from estury at newport was cut up as it was too bit to move and now stuck in a building on an industrial estate costing the tax payers thousands of pounds to store. it dont mention that does it about its recovery techniques!!
From memory they are pushing a new ballet so any wreck at sea which one wishes to recover will have more paper work that what its worth to recover. i think its comming into force 2010
I will try and find the link to post, my advise anything at sea better be recovered fast untill the put the kibers on it in uk waters