Dive site selection Be sure to check the weather, wind, and tides before going diving. Because there are so many dive sites facing different directions on Cape Ann, at any given time there is usually always a dive site with good conditions. Visibility - For shore dives, visibility is generally worse after it rains. The runoff washes dirt into the water, decreasing visibility. Plankton blooms during the summer months also decrease visibility.
Bottom composition has a large effect on visibility.
Generally, rocky or hard bottoms offer better visibility than sites with sandy or silty bottoms. Rocky dive spots are often slippery, especially at low tide when the parts of the rock that are always wet are exposed in the surf zone. Standing exits and entries put you at significant risk of falling and injuring yourself in the surf zone. Pay attention to the surf. While entering, put your fins on and try to swim out when the surf is going out.