Ice diving is a type of penetration diving where the dive takes place under ice. It is a risky type of diving requiring special training. Special training includes how to impact the underside of the surface ice if the diver`s weight belt falls off for any reason and the diver ascends uncontrollably and rapidly. Normal procedures and precautions for ice diving are: * use a snow shovel to clear the snow and ice from the area. * use 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 freeflowing - in this case the diver should immediately return to the surface. Some models fare better than others. * connect the diver and a 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. Two ropes won`t get tangled together, but three would. Because of a the water temperature (about 4°C in fresh water) exposure suits are mandatory. Some consider a dry suit mandatory; however, a 7mm wetsuit is also sufficient for hardier divers. It also has the advantage that it can be pre-heated with warm water. A hood and gloves are mandatory. Some prefer a to use a full face diving mask. Seven millimetre wetsuits are in common use by scuba divers in cold water areas (e.g., West Hawk Lake, Manitoba). It is common for recreational divers to pass below the thermocline in these areas while wearing a wet suit (and spend most of their dive there). The temperatures below the thermocline is typically 4°C. Therefore, if a 7mm wet suit is sufficient for a cold water recreational dive, it should also be sufficient for an Ice Dive.