Ok so i got a medical discharge from my navy last year. As for the medical reasons i got everything sorted now but they said i cant reenlist for another 3 years So i was thinking about the US military and i heard that it is possible. I planned to move to the US one day anyway.

I suspect the medical discharge will be detected by US medics and doctors because you will receive a detailed check-up , mate. Thery are no fools. Can't hide stuff from them. So, don't get your hopes up too high.

My medical stuff is all sorted anyway now. And of course, i would tell them about it if Brits can join.

Taylor, Yes you can, but you need to find a sponsor over here and go the immigration route.
Once here take all your papers: school, visa, Navy papers,licences,employment etc. to a recruiter of your choice. The rest is routine: Medical exam, induction, basic training, etc. Before you do all that however, find out if people who have served in a foreign military, are allowed to join the US military. There might be a loyalty conflict.

Ah thats just great. Immigration route would be hard.

There is no other way. Coming ashore in a dinghi from a submarine, or flying in on a Cessna won't work. The first thing your Recruiter will ask for is your passport, next your immigration papers.