I’m a union guy (former unlicensed, currently licensed), but can give you a unbiased opinion. As Capt_A put it, you are pretty much fucked. You get who you get, but union guys can, and do, get fired all the time. I don’t know which union you’re referring to. The key, if you want to get rid of someone, is to build a case. Just like on land. If they are a problem, or just incompetent, you can get rid of them. The usual course of action is verbal warning, written warning, discharge. I’ve seen guys written up and fired for the smallest infractions, because they were worthless, or a problem. I’ve seen guys miss the ship, and not get fired, because they were otherwise worthwhile crewmembers. Infractions for warnings or discharge can include anything. Poor steering, standing a poor or improper lookout, late for watch, not wearing proper PPE, violation of any company policy. Depending on the standing orders, I’ve seen a guy get logged for talking on the cell phone during gangway watch. Point is, if you really want to get rid of a guy, you can. The key is for the Chief Mate, Chief Engineer, and Captain to know the contract better than the crew. Most have never read it once. The contract works both ways. The crew must also abide by it. And remember, I’m a union man. But nothing’s worse than an AB who can’t steer. Except maybe a Mate who can’t make a command decision.