Chapter 10- Diving Techniques and Deeper Diving Diving Techniques and Deeper Diving 239 tion, there should be stable, designated decompression stops, additional air supply, and a surface support station. A decompression bar may be deployed from a boat for divers to hold while performing safety stops. In any body of water where there is surface wave motion, decompression on an anchor line is not recommended. A wave passing overhead at a 5 m (15 ft) stop can change your depth by the height of the wave. A much safer situation exists when a weighted line or decompression bar is suspended from mid-ship. This ensures your depth relative to the surface, eliminates anchor line jerking, and provides a stable, designated decompression stop. Extra full cylinders with regulators attached can be connected to this bar for use by divers who might be low on air. Alternatively, one or more 6 to 8 m (20 to 26 ft) long hoses from a cylinder on board can be hung overboard and attached to the decompression bar. However, divers should be well versed in gas management and self-discipline and should generally not require extra gas to be hung at the decompression station. The surface station will normally be a boat equipped with all emergency equipment and personnel listed above. It could also be a dock, pier, or even the shore if it is very close to a drop off. How close is very close? How long a distance can you, or do you, want to tow your dive buddy in case of emergency? PERSONNEL Your next step is to select personnel, which consists of your dive buddy and your support personnel. When you are selecting a buddy, look for someone who has equal or greater experience. It is a good idea to have made a few shallow dives with this person to ensure good communication and compatibility. You and your buddy will also need to make a mutual commitment to personal preparedness. You should be well rested, well nourished, have consumed no alcohol for 24 hours prior to diving, and pre-check equipment and procedures. A minimum of 20 dives in shallower water of the same type and location should be completed before venturing deeper. You should have a reason for diving deeper, rather than just to do it. Deep diving involves greater risk, including increased exposure to decompression sickness, and it is also a longer distance to the surface in case of emergency. Due to the possibility of impaired mental and physical function due to the effects of nitrogen narcosis, it is recommended to have support personnel (i.e., divemaster or dive guide). If applicable, the divemaster has overall responsibility for the entire dive, including: • Final confirmation of dive site with safe, acceptable conditions (i.e., depth, currents, visibility, weather). • Supervision and direction of divers and support staff. • Inspection of divers’ equipment and safety equipment. • Determination and recording of profiles. • Development and implementation, if necessary, of emergency procedures and accident management. The divemaster generally stays at the surface and supervises all aspects of the diving activity. The dive guide, sometimes referred to as an underwater tour guide, is generally a person familiar with dive sites. Dive guide responsibilities include: • Supervision of divers during entry, descent, stabilization (which includes establishing neutral buoyancy), the excursion, ascent, precautionary safety stops, and exiting the water. • Navigation and identification of special points of interest. • Assistance with any problems divers have of which he becomes aware. He is a guide, not a caretaker or babysitter. The dive guide goes in the water with the divers, and at many Caribbean destinations, the role of divemaster and dive guide are fulfilled by the same person. Deep diving requires a great deal of expertise. Participating in organized diving activities with trained professionals will increase the enjoyment of your dive.
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