For boatbuilding, you will want to use the 5000 and 6000 series alloys. See
Pollard's book, Boatbuilding with Aluminum
http://www.amazon.com/Boatbuilding-A.../dp/0070504261
.. NEVER use aircraft or other alloys, especially for use in salt water.

These alloys, down to about 3/16 thickness, can be welded. 1/8 is trickier,
and lighter gauge requires very specialized knowledge, experience, and
equipment, generally not appropriate for small-scale boatbuilding.


See Materials specification for 2024 - one of the more commonly used
aircraft alloys: