Solve a Mystery
The pump illustrated on this page stands about three feet high and is made of copper. The valve is brass and the threads accept MK-V diver hose fittings. The pressure gauge can indicate a maximum pressure of 50 psi. The only markings indicate the pump was made in the USA by US Gauge Company. The Technifacts reader who sent the photo stated, "[The writer and two other avid collectors of things diving] have located three of these old pumps. Quite frankly, we do not know if they were intended for diving."
The up and down stroke of the pump would make it difficult and tiring to maintain the constant pressure needed for life support of a diver. Also, I see no inlet for air. If the inlet for the pump is part of the bottom, it is more likely a water pump. Possibly two pumpers, one on each side with their feet on the flanges to hold the pump down while actuating the handle, could probably deliver 30 or 40 psi to a diver. Can a Technifacts reader identify this hand pump? If it's a diving hand pump, what country is it from? What years was it made? For what type diving gear? Write to E.R. Cross, c/o Technifacts, SKIN DIVER Magazine, 6420 Wilshire Boulevard, Los Angeles, CA 90048-5515.
BEATING THE COLD
After a long, cold and blustery winter most divers are beginning to think it is time to go diving. In so doing we will recognize that recreational diving is an adventure sport that involves known risks. The challenge of overcoming the risk factors through good training, good equipment, knowledge and experience may be our justification for voluntarily and freely choosing to meet and enjoy those risks.
One of the risk factors always present in all waters is hypothermia; a condition that can be insidious and not easily recognized. During prolonged immersion, this threat is present even in what we usually consider warm tropical waters. Hypothermia is defined as a reduction in core body temperature as a result of exposure to cold. The principal cause of hypothermia in divers is exposure to cold water. Unprotected divers lose heat to the surrounding water mainly by direct conduction via the skin. Water conducts heat away from a diver's body about 25 times faster than air of the same temperature. Even 95 Degrees F water can cause hypothermia without some thermal protection and after too long an immersion.
Heat is also lost by radiation but that is small compared to loss by conduction. However, in a cold environment, it is suggested that divers protect as many parts of the body as possible. This is particularly important before a dive but also may be advisable between and after diving. With this in mind, it is time to start thinking about how we are going to remain comfortably warm during the coming diving season.
A question that needs to be answered is: "How am I going to prevent even the first signs and effects of hypothermia?" Fatigue during and after a dive may be cold related. The direct cause of this fatigue is probably inadequate thermal protection.
Technifacts would like to thank Divers Unlimited International, Inc. for providing extensive information on hypothermia. DUI states, "The symptoms of unjustified fatigue may include tiredness after a dive, less dive time and loss of enjoyment."
To me the last symptom is critical. In his excellent book, Cold Water Diving, John N. Heine states, "Diving is no fun if you are cold." If diving is no fun why dive? In other words, for fun diving keep warm. Heine also points out that drysuits increase diver warmth, help conserve energy that results in less fatigue and keeps divers warmer while on the surface between dives. For a copy of this book visit your dive shop or call Best Publishing Co. at (520) 527-1055; fax (520) 526-0370.