There have been many threads about this. Scan back through the forum, and you can find all kind of advice.
Also, look here,
http://www.piratesonlineforums.com/f...getip&p=129157, but this assumes a progression from the beginning of the game, and unlimited access.
Lastly, I believe TSC is correct, if you allow your account to go to basic, you no longer have access to any warships you may have bought. So, keep your light ship, whichever style it may be.