We've fought for ages over using MARINE as the name of the World Government's Navy. Is it passable English?
I may have located a way to make it work.
In the United States, the commercial shipping lines are the Merchant Marine. As I understand it, in the UK, they call it the Merchant Navy (please correct and ignore me if I'm wrong– it's based on me noticing that there were 'Merchant Navy' class locomotives named after shipping lines).
So we have a real-world situation where 'Marine' can be a synonym for 'Navy.'
Everyone can relax now. Wear your MARINE hats with pride.