|
|
|
WHY
DIVE
DRY
?
Your exposure suit (drysuit or wetsuit) should
keep you in thermal balance with the environment. Anytime you have a heat loss
to the environment, hypothermia can set in.
Once shivering occurs (the body's natural response to re-warming when the body core
temperature drops to 96.1°F/35.7°C) hypothermia has already set in (beginning at 96.8°F
/36°C). At a core temperature below 96.8°F/36°C, diving operation should be
discontinued. At 93.2°F/34°C, temporary amnesia may occur and between
86-89°F/
30-32°C, cardiac irregularities occur and unconsciousness may result.
|
Your body responds to diving in cold water (less then 70°F/21°C)
in several ways:
-
Air consumption increases in colder water3(Fig. 1) and air consumption is
directly related to heat loss from your body (Fig. 2).5
-
When a diver is chilled in colder water, the heart rate and blood pressure
increase due to thermoregulation.
4,6
-
In 39°F/4°C water, divers suffered impairment in the ability to judge time. Mental performance was impaired for
tasks that demanded concentration and short term memory. 5,7,8 When the core body temperature falls
to 95°F/35°C or below, confusion, increased difficulties in concentration, and physical stress
ensue.5
So no wonder you are uncomfortable when your body goes through all of these physiologic responses! Even if you
don't sense these responses, research has shown that divers may not be the best judge of their hypothermic state.
9
The answer to thermal equilibrium while diving is a drysuit. The simple point is that it is easier to heat air
(i.e. drysuit) than water (i.e. wetsuit). For thermal equilibrium, a drysuit beats a wetsuit merely due to the
laws of physics. To heat the same volume of water by 1°C, it takes 3,200 times the amount of energy as it does to
heat the same volume of air (Fig. 3).10,11 Keeping warm in a drysuit
requires very little energy
from your body and it is easily achieved.
|
|
|
  
|
Wetsuits lose 42% of their insulation capacity at 2 atmospheres of pressure (33
feet in seawater) and continue to lose insulation value with depth. 12
Furthermore, exercise in a wetsuit doubles the heat loss through conductance which
is attributable to the flow of water under the wetsuit. 13 Comparisons
of 6.5mm wetsuits with conventional drysuits have shown that drysuits lose much less
of their insulating capacity (clo) with depth as compared to wetsuits (Fig.4).
Diving in a wetsuit below 70°F/21°C presents severe thermal challenges due to
the heat loss that occurs with depth and the thermal inefficiency of a wetsuit.
In order to dive in thermal equilibrium, "the optimum thermal protective
garment for divers (1) should have an adequate insulative layer that is
unaffected by depth, (2) should mot be significantly compromised by water
flow, and (3) should be provided with a gas layer which has an insulative
value equivalent to air at 1 atmosphere."14
Diving Concepts offers drysuits that excel in fulfilling all of these
criteria.
In the next few pages you will see why Diving Concepts drysuits are the latest in
drysuit technology. If you want to dive in a warm, comfortable and streamlined
fashion with a drysuit that fits you well, a Diving Concepts drysuit is the right
choice for you.
WHY
COMPROMISE?
|
Company Info
| Why Dive Dry
| Catalog
| Local Dealers
Contact Us
| Home
|