Straight to the point, the actual snorkeling itself is ok... there were lots of fishes to see though the reef itself wasn't too healthy. The water is clear enough and the equipment was functional, though really seasoned. So on that saving grace, it didn't get the terrible score.
On everything else, it's really poorly managed. It's as if the staff and crew were forced to take the group. Boy was everyone grumpy. Instructions were shouted out as if we were little kids, there were little disregard for our native language with all orientals assumed to be Mandarin speaking, and everyone was simply herded from place to place with no clear directions and handed off in succession to different staff members who were not easily identified.
Depending on what you paid and where you booked from, you are either picked up from your hotel (my bus came 30 minutes late) or make your own way to the jetty. You're then tagged with a wristband and then herded to a rickety ferry with inconsistent air-conditioning. After an hour, your arrive at this anchored platform and instructions are shouted at. An ok lunch is provided and there are fresh water showers so everything was functional. You get just over 3 hours to snorkel at your leisure and at certain times boats to shore and glass bottom boat rides take off.
What to expect? Poor service, grumpy staff, hardly any smiles, and nothing is on time except departure. You will get a chance to snorkel (and dive if you pay extra) which really is the saving grace. Do wish the reef was healthier but it is a tourist trap with an anchored platform so how healthy can it really be anyways. Explore different sites before booking as prices for the same experience varies widely.