Hi Doc_Z,
There are boats in the "airplanes" folder. I have all of my Deltasim boats in that folder (including the tug), as well as the oil tanker and a masted sailing ship. (to mention a few). The AI boats are in the "boats" folder. The airplanes folder is where the ones you get to drive are located.
The repaints go in the respective vehicle's texture folders (one for each repaint). The oil tanker and SH_High Seas tugboat should be installed prior to applying any repaints, of course. Then follow the instructions that should come with all repaints. Let me know if you need more specific help with this, ok.
Oops! ... just realized we are "off topic" here. Sorry.