Things in the UK, Australia, and Europe in general are far more restrictive than they are over here. If I found some cannons in a muddy river, you can bet your a$$ I'm going to salvage them. That man-o-war found in the Thames was left for centuries to rot and then all of sudden the government cares when divers find it and want some awesome keepsakes?
I've heard about people tearing apart wrecks for the wood to use as furniture. Now if the wreck is a busted up pile of wood that has no historic value to it, then by all means go to town. However if we're talking about a warship from one of our wars (only 4 major ones were fought on our soil), that may require some deliberation. If it's a wargrave were we have remains on it, then that's the line that should be drawn.
The Mary Rose was left to rot for hundreds of years. Should the club that found it have made a nice table and chairs out of it?
All that rubbish the Romans and Egyptians left lying about? Just let people pick it up and decorate their bathrooms?
Most of the real wrecks involved people dying. Some of the most tragic were not at war. In a war there is a point to it at least. Some drunk or idiot in charge of a ship load of people gettting it wrong is a tragedy too.
Do the T&Cs exclude calling someone a philistine?