Calculating sea time

I had a question about calculating seatime I messaged the nmc and they didn’t fully answer my question. My question is working on smaller boats (less than 100gt) that only require a master and a mate by the coi and no other officers (and the company doesn’t staff extra officers anyway) combined with no person may work more than 12 hours in one 24 hour period and the boat must be under the command of a licensed individual, doesn’t that mean that the master and mate are working alternating twelve hour shifts?

More likely 6 & 6.

Ok fair. But they would still be working 12 hours in a 24 hour period, right?


When I worked crewboats in the GOM, we worked 12 hours on 12 hours off. Captain, Mate, 2 deck hands. Seatime was documented on company letterhead indicating 12 hour days on the two watch system per the COI. I always received 1.5 days credit per actual sea day on those boats.

Ok. The place I’m with now is being weird because they say they run 3 watches but only have two licenses so Im just making sure. It doesn’t matter that they say they’re running 3 watches for captain and mate it’s really only two

What type of boat, and what does the COI require for deck officers?

Currently just a 100 ft schooner. And coi only requires a master and mate.

If anyone looks this up hoping for an official answer the NMC says that it is up to the evaluator. But if you make a case in your letter you’ll probably be fine. I would say in this case to have your 12 hour day count for time and half as under 46 CFR 10.232 H,2. The COI states that there are only two officers 46 CFR 15.520 and that the vessel must be under direct supervision of a licensed officer. And watches of smaller vessels cannot exceed 12 hours unless in an emergency 46 CFR 15.710, 8104, and 15.705

You also have to consider and make a compelling case for the “determination” discussed in 46 CFR 10.232(h)(3). There is a good chance that NMC evaluators are not authorized to make such a policy decision, and it would need to be escalated to a higher level at NMC.