Through a hole cut in the High Arctic ice, Canada's latest pioneer will dive to lightless depths to fathom a mountainous undersea world unseen by human eyes. Shaped like a six-metre-long torpedo, Explorer will creep through the darkness at the speed of a briskly paddled canoe, under pressure so powerful it would crush a car into a block of steel scrap.In March, a small team of Canadian government and industry experts plans to launch the autonomous unmanned vehicle (AUV) in the eastern Arctic, more than 4,100 kms northwest of Toronto. The yellow craft will be on a critical mission to map the sea floor, at a depth of some five kms, as Canada rushes to compile evidence supporting its claim to a vast northern territory before a 2013 deadline.If the robot runs into trouble Explorer will have to think for itself. Using its pre-programmed wits, the vehicle will have to decide the safest way around who knows what in an undersea world it will be mapping for the first time in history. Then, if the lithium-ion batteries are draining, Explorer will have to find its way back to camp, searching for human masters adrift in the warming Arctic Ocean.International Submarine Engineering Ltd. (ISE) is in a select group of some 10 high-tech submarine companies competing for contracts around the world. It has sold more than 250 underwater vehicles to clients in 20 countries, including the U.S. Navy and major scientific agencies in Europe and Japan. "I've been building AUVs just short of 30 years now, and I've lost a few of them. But we've always got them back," says Ferguson, ISE's vice-president. "And we've always found out that the vehicle actually did what we told it to do. We just told it to do something that was not what we intended."If Explorer does end up at the bottom of the Arctic Ocean, there’s only one backup can carry on the six week mission. The pair of vehicles cost Canadian taxpayers $5 million.Losing one, or both, would be an expensive setback. To cut the risk of Explorer going AWOL in the Arctic, the team will use a powerful homing beacon, able to transmit 50 kms under water and will be conducting sea trials in Indian Arm.