New America Navy.

[Olefin]

I think the question would be more appropriate if any naval vessels joined up with New America eventually. Its strongly implied that the Florida cell was in the process of getting at least part of a CivGov Army unit to join up with them and that they were close to getting the Sea Lord's men to join up with them - which would give them a navy depending on what he had left.

And you can rearm ships - not with high tech weapons of course - but definitely with things like AA weapons and light cannon. A couple of tugs fitted with 20mm cannon and 50 caliber machine guns with some improvised armor would make an effective "navy" depending on what they were armed with.

As for what might be possible - look no further than the Last Submarine where a warlord came close to having an operational nuclear attack submarine.