seasickness cures????????

I have been fishing from party boats for 25 years but not nearly as much as I have wanted to because I get seasick. If it's anything more than 2-4 foot seas I can't go and 4 footers is pushing it.I can almost never go out on a private boat in the ocean. I have tried every over the counter pill , the patch, watched what I ate the day before, get a good nights sleep, nothing has worked. If anyone has anything else I can try please let me know. Any Navy cures??? Coast Guard cures???? Thanks