The only boat you can reskin is the patrol boat in SS2006. You can find it here: (assuming you did a default install)
C:\Program Files\Vstep\ShipSim\Actors\act_dynamic_objectsThe paintshop file is named:
Act_P6_Port_authorities_Custom.psdAfter you paint this file, you must convert it to a .dds file. (DXT1 or DXT5) The file will be named:
Act_P6_Port_authorities_Custom.ddsIf you have Adobe Paintshop, install the plug-in to convert the .psd to .dds, you can find the plug-in here:
C:\Program Files\Vstep\ShipSim\ToolsHope this helps.
EDIT: I use DXT1 as it is a smaller file and I can't tell any difference in quality.
WW