Is there a way (boat) to get from either Caye Caulker or Ambergris to Xcalak Mexico? Would appreciate some input from those of you who have done it. Thanks

Private Charter is the only way. Quite a long but interesting trip from Caulker, usually done up the West Coast of Ambergris. If you do a search on the main section you will see some posts on this and from memory some rough costs.

There are occasionally organised trips, if there's something going on in Xcalak that people here want to go to. I've been there twice and honestly it's a tip of a place.

I think Amigos del Mar dive shop in San Pedro have business up there from time to time, so you could always ask them if they know of any trips. Speak to the boss, Changa.