When we come across an incredibly deep ice cave, we just nod politely and comment on how cool it looks. If you're Tim Howell, then you go diving into that ice cave. Of course, you shouldn't attempt this unless you're incredibly fit and have the experience to cave dive like Howell does. He descended 130-feet (which is 120 more than we would go) and explored the natural cave. The only part of his adventure more impressive than getting into the cave is watching Howell and his buddies climb out.