Definitely Flying Cloud. Veendam's excursion was full so we went straight to the tourism office off the port and they hooked us up with Flying Cloud which turned out to be MUCH better than the ship's excursion and half the price.
They provide snorkel gear, munchies and beverages. On the way back in from snorkeling they turn the music up on the catamaran and everyone has a good time.
It was AWESOME!