I prefer the north reef near 700s (red line) given abundant live corals, schools of fishes and sometimes pleasant surprise with sea turtles. Two marked areas with an eye emoticon are where I spent more nearly 10 mins with the turtles, really unforgettable experience. It it easy to see schools of jacks, fusiliers, damselfishes around this reef. An whitetip reef shark was also seen. Versus the south reef near 700s (green line), I think this area has richer marine life with slightly better visibility under the water. This said, this reef is wavy due to winds so in the bad weather you might want to avoid this reef for snorkeling.

The south reef is also good place for snorkeling as it boasts decent marine life with relatively smoother tides. Easy access from the dive pier is another merit for whom do not stay in 700s villas. I also saw one turtle near 710/712 and there was usually a school of batfishes around here. Near 626/628, I also saw schools of fusiliers etc staying around for multiple times. Between 612-628, you can enjoy really calm circumstance as 600s island blocks waves from north.

The reef around 200s facing southwest did not have rich marine life like 700's reefs but still okay to go. Also there are little tide so it is easy for comfortable snorkeling. I recommend you swim towards Glow, not 213.

Avoid areas highlighted by purple lines... simply they were too mulky perhaps due to sands and lack of corals?

Overall my snorkeling experience at WA was marvelous. I hope the underwater environment to get even better til I come back!