Ice diving is a type of penetration diving where the dive
takes place under ice. Because diving under ice places the diver in an overhead
environment typically with only a single entry/exit point, it is considered an
advanced type of diving requiring special training (although whether it
constitutes "technical diving" is part of a wider debate within the
diving community). Ice Diving should not be attempted by anyone not trained (or
in training) by a qualified instructor.
This special training for ice diving includes learning about
how ice forms, how to recognize unsafe ice conditions, dive site preparation,
equipment requirements, and safety drills. Ice divers are tethered for safety.
What this means is that the ice diver is wearing a special harness under
his/her scuba unit. A line is secured to this harness and the other end of the
line is secured to the surface by one of a number of methods.
Ice diving is a team diving activity because the ice divers
line requires a line tender. This person is responsible for playing out and
taking in line so that the ice diver does not get tangled. Communication to the
ice diver, or to the surface, is accomplished by pulling on the line. Each
series of tugs means a different thing. There is an ice diver suited up and
ready to enter the water at a moment's notice. This ice diver is a safety
diver, and has his own tender. His purpose is to assist the primary ice diver
in the event of a problem.
Training for Ice
Diving
•How to
impact the underside of the surface ice if the ice diver's weight belt falls
off for any reason and the ice diver ascends uncontrollably and rapidly.
•How to
deal with a frozen air supply system using a redundant back up system.
•What to
do in the event the ice diver loses contact with the line or the line tender
does not get feedback from the ice diver in response to signals given to the
diver.
Ice Diving Equipment
Since diving under the ice takes place in cold climates,
there is typically a large amount of equipment required. Besides each person's
clothing and exposure protection requirements; including spare mitts and socks,
there is basic scuba gear, back up scuba gear, tools to cut a hole in the ice,
snow removal tools, safety gear, some type of shelter, lines, and
refreshments[citation needed] required.
Procedures and
precautions
•use a
snow shovel to clear the snow and ice from the area.
•use an
ice saw or a chain saw to cut a hole in the ice.
•use a
weatherproof area for the divers to suit up.
•use a
diving regulator suitable for cold water use. All regulators have a risk of
freezing and free flowing - in this case the diver should immediately return to
the surface. Some models fare better than others. Good practice - two
unfreezing regulators arranged as following: first stage number 1 with primary
second stage, BCD inflation hose and Submersible Pressure Gauges, first stage
number 2 with secondary second stage (octopus), dry suit inflation hose and
Submersible Pressure Gauges.
•connect
the diver and tender on the surface with a rope and harness. The harness is
typically put on over the dry suit but under the BC or other buoyancy device so
that the diver remains tethered even if he or she must remove his or her air
cylinder or buoyancy control device. The harness fits over the shoulders and
around the back such that the tender on the surface can, in an emergency, haul
an unconscious diver back to the hole.
•use rope
signals.
•have a
standby rescue, roped diver ready on the surface.
•have one
or two divers diving at the same time from the same hole, each with their own
ropes. Using two ropes runs little risk of getting tangled together, but using
three significantly increases this risk.
Exposure Suits for
Ice diving
Because of the water temperature (about 4°C in fresh water)
exposure suits are mandatory.[3] Some consider a dry suit mandatory (neoprene
dry suits are recommended); however, a thick wetsuit is also sufficient for
hardier divers. A wetsuit can be pre-heated by pouring warm water into the
suit. A hood and gloves (recommended 3-finger mitts or dry gloves w/rings) are
mandatory, and dry suit divers have the option of using hoods and gloves that
keep their head and hands dry. Some prefer a to use a full face diving mask to
essentially eliminate any contact with the cold water. The biggest draw back to
using a wet suit is the chilling effect of the water evaporating off the suit
has on the diver. This can be reduced by using a heated shelter.
Ice Diving Outfit
Recommendations:
•Warm
waterproof shoes.
•Warm
anorak for cold weather.
•Warm cap
covering the ears.
•Sunglasses
with a UV filter to protect the eyes in sunny days.
•Lip care
stick and cream to protect hands and face against cold and wind.