A buddy of mine went on a singles cruise. They told him each ship was a 50% ratio of men and women. Ended up being about 90% men with 10% women.
He said it was a good time, he drank a lot of beer, and played poker with the other angry cruisers.
If you are actively looking for a woman, pof.com. Its a great place. I met a lot of great women on that site, had a lot of fun. Most of us weren't compatible for relationships but we had good times. Some of them I'm still friends with and see occasionally.
As for a single mans vacation I'd just start driving and see what I could see across this country before you need papers to cross state lines.