. >> this is a hydrophone. the electronic gear . >> this trip the doctor hopes to install 32 hydrophones located throughout tiger beach . >> each reefer receiver will tell you when it detects a shark with the receiver. >> the work has just begun. coming up next we'll find out if she's pregnant. >> we want to hear what you think about these stories. join the conversation by following us on twitter and at www.aljazeera.com. >> the peninsula, in arabic, is aljazeera. our logo represents courage. fiercely independent quality reporting. >> to take as much aid as possible... >> and standing up for the voiceless. when you see this symbol respected around the world it means you too can now count on all the things we stand for. aljazeera america. >> the very positive thing, and this it's underwater. that's really good. >> this is a tiger shark. >> it's not long before the platform is put to the test by an 11.5 11.5-foot tiger shark. [ yelling ] >> since the shark is dorsal finish up, tissue samples are taken first. and

killer, they had to remove the top two tubes so they could install on the exterior of that bulkhead hydrophones to include more sonar equipment to make it one that is capable of listening further distances one of the interesting factors about submarine life is the forward crew and after crew would compete who could reload a torpedo faster. it was back in those days they had a -- they're mechanical advantage was block and tackle which now days we have hydraulic system s systems so the guy had to be strong to move these torpedoes. this is not live now, this is the match 14 21 feet long, 21 inches in diameter and weighs approximately 3500 pounds loaded. it has two speeds. it's a slow speed it will go 36 knots for a distance of four miles. on high speed settings she'll go approximately 50, 51 knots for a distance of two miles. she is steam driven and she -- in this particular version it's a contact torpedo which means she has to hit the enemy to drive a pin into a pre-charge and then into the main charge. >> hundreds of men apply yearly for submarine training. they are draw unby the camaraderie of