Actually if it's in the reserve fleet it would probably be kept in a decent state, they have a significant maintenance program to ensure the ships can be put back into service. That's not to say that every ship in the reserve fleet would be seaworthy, some of the oldest ones are getting a bit "thin in the hull"
http://www.globalsecurity.org/milita...y/dot/ndrf.htm
What the global security writeup does infer though is that the longer a ship has be sitting in the reserve fleet, the greater the likelihood it will be scrapped or sunk (as artificial reefs)