10:04 AM PT -- Sources close to Blaine tell TMZ they're not dating and they've been friends for 20-plus years.

Round of applause for David Blaine ... dude produced a relationship outta thin air with super model Naomi Campbell, or so it seems.

48-year-old Naomi showed off her insane bod in this tiny bikini while cruising on a luxury yacht Tuesday in the south of France. Naomi's there with the famous magician who got some serious face-to-face with her. If they're dating, it's news to us but they sure do seem close.

Naomi did what super models do best ... strut her stuff for the camera. Selfies count.

David took a dip, but check out how he literally rose above the water. Haven't seen that on camera yet.