Ocean vs. Near Coastal Manning

My office is telling me that only 2 of 3 bridge watch officers need to be endorsed for oceans when making a non domestic water voyage(GOM to west coast via Panama Canal) on a non SOLAS classed less than 500 itc vessel. I find this hard to beleive, they allegedly found the proper cfr supporting this. Does anyone have the straight info on this and if so what is the supporting or non supporting cfr?

GRT of vessel, inspected? type vessel?

Not that it really matters but we have been doing it with two officers for the last three years…

I had permission from the COTP Miami to take a 900+ton ITC vessel from US to Brazil with 2 of 3 bridge officers endorsed for Oceans. What does your COI (or safe manning cert.) say? (assuming you have one)