It isn't illegal as such.
You're allowed to recover goods that are washed up on the seashore as long as you inform the official receiver of wrecks that you've rescued goods.
The owner can then recover the goods but has to pay you a salvage fee for saving his goods.
There's a fair few houses near where I live that were built with wood that washed overboard from a cargo ship years ago. (There's also one house that has a lintel made from one of the stones from a prehistoric stone circle.)
(, Thu 18 Aug 2011, 14:45, Reply)