Not to bring up old issues, since Keyshunter's response was from 2010, but wind at the surface over shallow water can easily generate a longshore current that will affect the diving, as it often does along the northeast end of the Jackson's bight section of the BBMP. He is correct that there can still be current with flat seas and that other factors drive most currents. But on Little Cayman in particular, one of the primary drivers of currents around the dive sites on the north side is how much water is being pushed into the BBMP from the east along the hard pan section of shoreline. Wind direction, speed, etc. will be an important factor in how much of a longshore current moves east to west along the north side of LC, and how far into the BBMP it pushes marginal visibility.