Chapter 2- The Diving Environment The Diving Environment 39 approaching a very steep bottom produce surging breakers. These waves slide up and down the steep incline with little or no foam production. Effects of Surf on Beaches In general, during the winter when storms are more frequent, waves break closer together than they do during the summer months. The shorter length winter waves break closer to shore and carry sand offshore, exposing rocks on the beach and in the surf zone. During the calmer summer months, wave periods are longer, and the waves break well offshore, washing sand back onto the beach, and covering the rocks again. Traveling divers should bear in mind that the seasons are opposite in the northern and southern hemispheres. Surf Passages The wave patterns and surf beat must be observed to determine when and if it is desirable for divers to make a passage through the surf zone. For entries on gradually sloping beaches, you should be completely outfitted (wearing fins) and should shuffle into the surf sideways or backwards while watching incoming waves over your shoulder. Knees should be slightly bent to maintain balance when standing in the surf zone. Maintain a wide stance for support and a low center of gravity. If you fall or are knocked down, remain horizontal and swim or crawl rather than trying to regain your footing. As soon as the water is sufficiently deep (about thigh level), you should lie down and start snorkeling. Swim under incoming waves. If a float is used, it should be towed behind you through the surf zone. Secure your regulator second stage(s) to make sure they stay off the bottom to avoid contamination with sand or silt. It is also an option to make the entry breathing on the scuba unit if desired. A high surf on a steeply sloping beach can be dangerous for a fully equipped diver. The surf zone is only a few feet wide, but the waves break violently directly on the beach. Your feet may be swept from beneath you if you enter while large waves are breaking. The waves could potentially break directly on top of you. When conditions are severe, it is best to seek a safer alternate location. If conditions are reasonable, the following procedures are suggested: FIGURE 2-8. IT IS USUALLY EASIER TO CRAWL OUT THAN TO TRY TO STAND BACK UP DURING A SURF EXIT. • Have your BC partially inflated for slight positive buoyancy. • Be fully equipped. • Get as close to the water’s edge as possible after timing the sets and lulls to coincide your entry with the smallest waves. • Enter the water as quickly as possible immediately after a wave breaks and swim beyond the surf zone quickly before the next wave breaks. This is an advanced skill. Surf entries over shallow rocks or coral are potentially hazardous and require special training to prevent injuries. While walking, it is best to keep a low center of gravity by crouching slightly, in order to avoid falls. When the water is deep enough to swim, put on fins and mask, wait for the onrush of water due to any waves present, and swim briskly to deeper water, being careful not to swim into rocks or coral heads. Such entries should be avoided until the proper procedures are developed under the supervision of a trained and experienced NAUI instructor. When exiting through surf, stop outside the surf zone and evaluate the surf conditions. Your exit should be timed so you ride the back of the last large wave of a set. Keep a hand on your mask and your regulator in your mouth if waves are breaking on you in the surf zone. To exit through spilling breakers, swim toward shore to waist-deep water, stand, turn your back toward the beach, watch the oncoming waves, lean forward with
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