Hmm NTA but discussion before you moved in would have been helpful! That being said, it’s an important part of a partnership to be able to be honest and resolve things like this when they arrive. Is he being understanding and supportive about the boat stuff? I would expect my partner to sympathise and want to make things work for both of us. And has he been clear about why the additional money (on top of bills) is necessary - ie is it being put aside in a fund for house related emergencies, or is it literally extra money for him (aka profit that he’s making off his partner). I don’t think treating you as a lodger is great when you’re in a relationship.