'Entourage' Director Doug Ellin -- Bikini Shoot Goes Overboard

"Entourage" director Doug Ellin had a brush with disaster on a yacht this weekend in Miami -- accidentally dropping his expensive camera into the ocean ... after shooting a wild bikini scene for the movie ... but thankfully, the damage was minimal.

Sources on the set tell TMZ, Ellin was stepping off the yacht onto a smaller boat when he accidentally dropped his personal camera into the water. He offered to pay divers $1,000 to find it, but it was impossible.

Luckily, the camera didn't contain any official film footage ... but it did have more than 500 behind-the-scene photos of all the girls in bikinis. Arguably a bigger loss.