Medical Examination
Divers should ensure they are fit and healthy to dive and diver training or diving must not be undertaken if the diver has had any recent medical conditions. If the diver has no underlying medical condition that would potentially prevent them from diving safely, they must sign the necessary club forms and a copy should be retained in club records. If a member has an underlying medical condition or query, telephone contact should be made with a medical doctor for further advice before diving with the club.
If any member has been the subject of a decompression accident they must not commence diving again until medical clearance has been obtained from a medical doctor. Some countries have local regulations that may require a medical examination so it is worth checking before traveling and diving abroad.
Potential new members who are undergoing the 'Experience Scuba' introductory course should be asked to sign a disclaimer, which states they have not suffered from diseases or conditions which would make diving hazardous.
Mixed Gases
The terminology 'mixed gas' can encompass many types of gases a diver could use. However it is generally accepted that the term 'mixed gas' usually means adding Helium to the breathing mix and Trimix (oxygen, helium and nitrogen) is the most commonly used mixture. Since Hoofer SCUBA is considered a recreational club, we do not condone the use of mixed gases during club sponsored dives.
Neutral Buoyancy
Neutral buoyancy is achieved when the diver is able to remain in a static position in the water and rises or falls as a result of breathing in and out. Comfortable diving means the achievement of neutral buoyancy, if required, at any stage of the dive.
Correct weighting is critical to gaining neutral buoyancy easily, the diver should carry just enough weight to hold a 15-foot safety stop with a nearly empty cylinder. An inflated drysuit is not a good solution for the sole purpose of neutral buoyancy. Drysuited divers must wear a buoyancy compensator to maintain and control buoyancy safely.
Night Diving
Night diving requires very careful planning. Each diver should have a working dive light otherwise the dive should be terminated. Each diver should carry a backup dive light or some other means of identifying their position if their main light fails. An efficient system of marking the point of exit must be employed. Care must be taken with diver-to-diver signals to ensure that the light is not shone directly into the diver's eyes. Likewise it is advisable not to shine lights into the eyes of fish as this can startle and disturb them from resting at night.
Nitrogen Narcosis
Nitrogen Narcosis decreases a person's ability to cope with emergencies, slows down reaction and realization time and increases the risk of an accident. There is strong evidence to suggest that 130 feet should be regarded as the maximum depth for most sports divers, as below this depth narcosis problems can become debilitating.
Nitrox
The use of Nitrox (nitrogen/oxygen mixtures where the oxygen content is greater than that of air) as a breathing gas can provide a safety benefit in terms of a reduced risk of decompression illness, or enable longer dive times/shorter decompression stop requirements with no added risk. The use of Nitrox has certain disadvantages that require training and suitable equipment to minimize the risk.
Properly trained and qualified Hoofer SCUBA members are permitted to use Nitrox on club dives. Divers not trained in the use of Nitrox may not use it for any dive. PADI recommends a maximum partial pressure for oxygen exposure when diving of 1.4 atmospheres absolute (ata). This figure will determine the Maximum Operating Depth for any Nitrox mixture. Failure to observe the Maximum Operating Depth for any gas mixture may have fatal consequences due to the onset of oxygen toxicity.
Also see Cylinders (Nitrox and Mixed Gas).
No Clear Surface (Cave Diving, Ice Diving, Diving inside Wrecks)
Members wishing to dive in caves should contact the appropriate cave diving organizations, as this is very specialized diving, in terms of technique and equipment, and is not covered in Hoofer SCUBA diver training.
Diving under ice should only be undertaken with a surface party of at least two. This allows one to tender the divers, while the other is free, if required for any reason, including an emergency. One of the divers must be securely roped to the surface, if diving in pairs, and contact between them should be by means of a buddy line.
Wrecks should not be penetrated without proper training and equipment.
Also see Wreck Diving.
Odd Numbers
It is very strongly recommended that diving in 'odd numbers' be avoided, as the 'odd man out', to some extent, is without a buddy.
Also see Buddy Diving.
Oxygen
The administration of 100% pure oxygen following a decompression accident is recognized as an effective FIRST AID TREATMENT and may result in much less serious injuries. It SHOULD NEVER be regarded as a substitute for recompression, which is the only effective treatment in such cases. Members who have taken part in appropriate training courses and who have approved equipment, are recommended to use oxygen to treat divers showing symptoms of decompression illness, while they are waiting for recompression treatment.
Where 100% oxygen is unavailable as a therapy gas, a Nitrox mixture may be used, although the benefit will be much less than that of pure oxygen. The use of Nitrox mixtures containing up to 40% oxygen is permitted for diving by properly trained and qualified Hoofer SCUBA members. Mixtures containing more than 40% oxygen are NOT recommended for use by recreational divers.
