Suppose you are a junior deck officer on a boat

In a recent discussion among friends the answers to the following ranged from “no harm no foul” to "everyone loses their license.
To keep is simple, assume the boat is a 100-ton near coastal boat. Assume the COI says you must have a 50-ton captain and edit (oops - I meant two 50-ton mates - not 150 ton) and the boat operates 24-hour days. If one of the mates only has a 50-ton mate license, does the other mate have a potential liability issue? And what would the captain’s liability, if any, be for operating such a vessel.

Does the Capt own the vessel?

Hmm, 100 ton NC boat with a 50 ton captain. NO GO! Should sit at the dock. The USCG screwed up on the COI. It would be the 50 ton captains responsiblity to “catch” the error and notify the OCMI.

I was using this as a simple example in tha abstract. The discussion was drawn from a real situation. A regular company where one of the mates had too small a license. All crew were employees. tThe capatain was not the owner. It was a non-profit organization.

I’m sorry but I’m confused by the original post. What, exactly, does the COI call for?

It was the captain’s responsiblity to check the license of all required licensed crew. It all falls on him, even if the company sent the mate to the vessel.

I was in a discussion about what if any responsibility other crew members have if a vessel has a person in a position that violates the minimum manning reguirements. Specifially, what would be the responsibility of an OICNW if another OICNW was not in compliance with minimum manning requirment. For example, what if the chief mate had too small a license? Suppose you are the third mate and you are aware that the chief mate’s license is not in line with the requirments of the COI. What ,if any, is your liability operating as a OICNW? Suppose the captain is incompacitated and the chief mate takes command. And the third mate is now the second mate. What then…
Related, suppose you aware that the chief engineer does not have the required certificates?

It is fairly simple, if you as the Master are aware of manning that is not in compliance with the COI, you don’t sail until you are. If you are a Mate in that situation, and the Master chooses to sail, you have a choice either to leave the vessel before it sails, or join in the non-compliance and take your chances.

Interesting situation. We had a relief chief that worked in that capacity for several months. Not the office, master or chief engineer checked his license. Finally (about 6 months latter) everyone had to show their license and another chief eng noticed it. They took him out of the position and off to another boat. Amazing - NO ONE BOTHERED TO CHECK! What amazed me, is the office specifically sent him to the boat without checking!

This is not all that uncommon, although you’d think it would be. Although the CG may choose to take action against the company and/or the individual in personnel who didn’t properly vet the mariner before sending them to the boat, if anything it’s usually just a fine as they don’t normally have a license to go after. The buck stops with the master, fair or not. Proper licenses, MMD’s, STCW letters and TWIC’s must all be checked and accounted for. I also ask in advance / check for valid passports (when required). And until the day comes, if ever, that the TSA and the terminals consistently accept the damned TWIC (let alone an MMD) it would be a good idea to make sure your crew has valid state drivers licenses or passports on their person to serve as ID so you don’t wind up unexpectedly losing someone at the airport security checkpoint or the terminal gate. It sucks to have to play den mother all the time but it sucks even more to have to explain to the CG why you need to sail short. Or you can just take your chances…