I dont feel that the trait for the Marine is fitting/ unique for a naval class. I feel it is more of a thing youd give to, for example, a highlander regiment. However I cant come up with any good suggestions sooo..... ¯\_(ツ)_/¯
I also think the Marine should be able to use some basic controls on a ship, be it lowering a rowboat. Something that doesn't necessarily have with the actual ship itself to do.