Anthony Bourdain -- I Went BALLS OUT in Naked Pics

A year before releasing the book that launched him to infamy -- "Kitchen Confidential" -- chef, author, and professional ramblin' man Anthony Bourdain let it all hang out while on vacation on St. Martin ... and TMZ has obtained the ballsy photos.

We spoke with Anthony ... who told us the pics were snapped by his now ex-wife Nancy in 1999 -- capturing Bourdain and his best bud/sous chef Steven Tempel in their element.

Anthony tells us, "I look good! Nice tan. As I haven't seen the photos without the star, I can only hope the water wasn't too cold that day."