Sea Or Land

I went on a boat ride about two weeks ago and just before i board the boat i remember i have my weapon on me ( i am so comfortable with my gun it does not feel any different than a cell phone ) the question is Does your cwl valid on sea as well as land ? or do you have to give it to the captian ontill you return to port ? or does it depends on how far out to see you go ? I left it on land to prevent any misunderstanding but the thought accored that the car could get broken into while you were at sea