. >> we are now passing through the narrowest part of the bering strait, where we've got the united stateso my left, and to my right, just 50 miles away, is russia. now during these warmer months hundreds of ships are passing through here, and that number is expected to rise as the levels of sea ice recede. and the bering strait is important to more than just ships - it is also a major migration way for hundreds of thousands of marine mammals every year. >> plan is to finish the brief here and then go in to the launch and recovery of the puma unmanned aircraft. >> it's just before 8:00am, july 9th... time to find out what this mission is all about. healy's first test of the day... an automatic capture system for a remote controlled aircraft. >> equipment? how confident are we in the machinery we're using, how reliable is it? >> before every operation, a briefing is held to determine risk. everyone involved gets to weigh in. >> i see a three... four. >>the higher the number, the higher the risk. >> i recommend we proceed sir. >> there will be a lot of traffic coming through here and with in

finally, the bering strait and pearl harbor. you see the captain, navigator we had on board. he was the first to think of these trips and had much to do with the development of the sonar that was used. dcc dragon on the water. -- uc see dragon on the water. we had a fantastic underwater television. here was a picture taken by one of our scuba divers. in 1960, there were some people who thought the ice was perfectly flat underneath. some may not know about 9031, he bought a surplus world war i u.s. submarine for a dollar. in 1931, he had it equipped with a huge sled runner on top of the summary. the idea was to skate along underneath this wet ice, drill a hole whenever you needed air to render engine. we were lucky they never got underneath and the crew didn't need it. if they got under this, that will be the last we saw of them. it went to aircraft controls. i took this picture in baffin bay. that iceberg is 308 feet above the surface, over 1000 feet beneath the surface. the profile of teddy roosevelt was actually there. we can go under that. we went underneath another 32 ice