Well, for that past month there has been an algae plume surrounding the Virgin Islands. It has caused the water to be a different color and reduced visibility drastically. It seems to be finally dissipating but is still lingering. Divers and snorkelers have noticed the difference but it hasn't stopped them from enjoying the Caribbean water. We haven't been out in awhile so I can't describe first hand, but friends have said the water is greener and the visibility is like 10 feet vs. the normal 40-50 feet. Here are a couple articles in the St. Thomas source that give more detail.