Jon, It has been years since I sat for my Captain's exam and don't remember what is in each Rule. Could you please provide a link that I can review? Thanks!. Lights will be a consideration for Ft. Pierce water operations especially if there are night operations. Accommodations and dock space are right next to a US Coast Guard Station so we will also have to display the correct shapes, flags, and lights on attending surface vessels to denote "Conducting submerged operations, restricted in maneuverability" and these must be visible from 360° around the dive site. R/Jay -----Original Message----- Jay, I don't see anything in COLREGS specific to submarines except that naval submarines have various exemptions and customized lighting as deemed reasonable. I believe the ABS requirement for a location device is limited to just that, aiding in location of a sub that has surfaced. However, you make a good point about COLREG lighting which is a requirement we haven't talked about much. If Rule 22(d) applies to small subs then things are not too bad. But if we fall under Rule 22(c) then we should probably be looking at some reasonable solutions that will survive a bit of external pressure. Jon |