So me, with my 1400 posts and all, going on our 4th DCL sailing in 4 years vowed to be more prepaired than EVER!!! So yesterday while fill out my mail stop cards say "hey, I need some stamps". So I purchased 5 books............but, I'm going to cozumel and GC.....I don't want to sign dumb but what stamps do I use? 1 mexican and 1 u.s?