Thanks to the combined wisdom and experience of many on the St. Croix forum, here's a description of some snorkeling spots on the island which should be useful to others. I will be linking this to TopQuestions about St. Croix in the upper right hand section of the Forum page so feel free to add to this posting so that we get a complete list of snorkeling spots.
BUCK ISLAND - Did reef on NE side as well as reefs on West Side. Obviously the reef is mostly dead, but it was still a great time and I plan on it again... Love just hanging out here for the day. Bunch of BIG cuda's but they don't spook me.
RAINBOW BEACH- mostly schools of one species of fish, good amount of sea turtles which was nice.. Beach is great.
CANE BAY- long swim to get to "Wall" with nothing much along the way. Wall seemed a bit too deep for snorkeling
GROTTO BEACH (Buccaneer)- Actually a nice little "reef" due to the angle of it forming a ledge for fish and lobster to hide under. I actually enjoyed this and the swim around to Mermaid beach...
JACKS/ ISAAC'S- a lot of grass... and a little spooky with absolutely no one else around. Very peaceful area.
CAY (In Christiansted Harbor) - swam around it just because I was there... Nothing much... Some nice size Cuda
TEAGUE BAY REEF- I paddled out to this reef in kayak by myself. It was a bit rough, so I held onto kayak. I was in the water for about 3 minutes and saw some 5-6 ft reef sharks cruise by and got a little spooked (they looked like Bulls but I think they were Carib Reef Sharks). Anyways I'd like to come back here when WITH someone...
TAMARIND REEF - the folks at the beach shack there will let you know if wind conditions are good or not....when choppy this is not as fun and visibility is down....with no chop this is a great trip, lots of soft corals which bring in turtles, stay in 10-20 foot depth all the way to the west end point,
DIVI BEACH - We also like a spot just west of Divi. Park near the Pizza shack at Divi and walk west on the beach until you get to the two palm trees that hang low over the beach. Enter here in very shallow water...get on your belly quick to avoid urchins....swim out to offshore reef about 50 yards...the reef parallels the shore all the way down in front of the Divi but be careful becasue at that point you are far offshore...as always this trip is better when the wave action and visibility is reduced due to low wind.Edited: 6:05 am, November 18, 2012