I was surfing the web looking for material and ran accross this ...
But downright crazy? stolen from Phil Graf of Omni Divers
this is not Phil
Some people consider scuba diving adventurous, maybe even a little risky. Many more people would consider ice diving not only adventurous and risky, but downright crazy! Those people are missing out on a lot of underwater fun! This unique type of diving requires a lot of set-up and the ability to stay mindful of safety precautions, but it is an experience that should not be missed. The visibility is usually better under the ice because there is less algae and microscopic life forms to cloud up the water.
Just like regular scuba diving, a fair amount of preparation must be done before you hit the water in ice diving. According to Phil Graf of Omni Divers in Oregon, the first thing that needs to be done when you reach your dive site is to cut a hole in the ice.
Using a chainsaw or an ice saw, and a breaker bar (a thick iron bar that can be used to break up ice), cut three dive holes. Because the dive hole is the only place that a diver can surface, it is considered a good idea to cut more than one. The idea is to cut two accessory dive holes on either side of the main one as emergency exits, should divers become disoriented or need to surface immediately. Then shovel lines of snow away in the shape of a giant asterisk with arrows pointing to the dive hole. (From the air it must look not unlike those mysterious crop patterns that are found in England.)
mysterious crop pattern
Because the snow on the ice blocks light from penetrating the water, the back-lit designs can be seen quite deep in the water, directing the diver to the main dive hole. After cutting triangular holes in the ice, the loose piece is anchored in the point of the hole and tethered back so it will not move in and plug the hole. This piece of ice should be replaced back in the hole after the dive to keep anyone from falling in. The hole will need to be marked even after filling back in, because the ice block degrades badly during the diving operation and it will not be stable for quite some time afterward. If the hole is left unattended, it must be marked and guarded as well.
relaxing
after a dive
Except for comfort during changing, a dry suit is not required and a 7-millimeter wetsuit is sufficient. A hood and three-fingered mitts are also needed to remain comfortable. Other items required are ropes, harnesses, carabiners, short rope and bars for anchoring the ice blocks in the holes, a tent, heaters and a unit for boiling water at the dive site.
Keep in mind that an extra air cylinder must be on hand because you will need to have a safety diver ready to go, even on the last dive of the day. Arctic regulators are not a required item, but special precautions need to be taken when entering the water as a regulator will freeze up and free-flow if it is used above water in sub-zero temperatures. It is important to put your head under the water then place the regulator in your mouth. Each ice diver wears an ice harness under their BC. The tender (verified by the diver) then attaches one end of a 100-foot line off to the two D-rings on the ice harness. A tender on the surface keeps track of the diver and the slack of the line. The free end of the line (tender end) is tied to an eyelet on a stake that is driven at an angle into ice.
More people are also required for ice diving than other scuba diving activities. One person will function as the line tender and another will be a safety diver, suited up and ready to go. One person should tend to the boiling water and another should keep the circles clear and wet for the best visibility and light penetration under the ice. There should also be divers tending the holes, keeping them free of ice and blockages. Two people can be diving under the ice. Each person can rotate through the positions so that everyone will experience one of the best ways to dive. A minimum of six people is required and all divers should have at least an advanced open water certificate. More people are better, as it can be a lot work to shovel off the circles and radiating lines.
Have you seen those inkblot pictures they show in psychologists’ offices on TV? That’s what the underside of the ice looks like when your air bubbles smash into the "crystal ceiling." You’ll spend the majority of each ice dive hovering on your back a few feet under the ice, just watching your bubbles. As you’ve seen countless times before while diving, your bubbles get bigger and more swollen like a jellyfish mantle as they ascend, but when you are ice diving you get to see them shatter with dramatic force against the underside of the ice. When a large bubble shatters, it is like watching a bucketful of diamonds being thrown out onto a mirror. These tiny glittering puffs of air bounce and tumble and roll about as individual gems for a moment or two until they rapidly begin joining forces once again and slither into blob-like shapes that eerily slide off into the dark nothingness of your peripheral vision. It’s very "trippy!"
updated 2/15/05