We booked a snorkeling tour more than once in Mexico, thinking that perhaps "this just wasn't a good day." In our experience, there IS no good day to snorkel either in Cabo or Cancun, regardless of beach or locale. The beaches are generally rough, stirred up, and the ocean floor is invariably sandy---so the only snorkeling "coral" tends to be treacherous rocks jutting from large outcroppings here and there. We booked a snorkel boat to take us near Los Arcos, which featured crowds of several boat operators jammed into together and a guide who threw chunks of french bread into the water to attract fish. Seriously!? Several feet away were tiny fishing boats, one with a guy vomiting over the side. Bottom iine: Mexico is not a good place for snorkeling. Go to Hawaii, Australia, or elsewhere if snorkeling and viewing beautiful fish is your thing -- otherwise you'll waste your money and snorkel in the equivalent of mucky bath water.