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Dr. Edie Widder : Submerisibles

Both ALVIN and Johnson Sea Link are submersibles. The difference between a submarine and a submersible is a submarine has enough power to leave port and come back to port under its own power. A submersible has very limited power reserves so it needs a mother ship that can launch it and recover it. The ALVIN has a noble history, and it can dive a lot further than the Johnson Sea Link, but there are also many, many advantages to the Johnson Sea Link, the biggest being the visibility. You cannot appreciate that until you've gone down and experienced that looking through a porthole versus looking through that fish bowl shape that is the Johnson Sea Link. You can see everything around you. It makes a huge difference in what you are able to see and observe. The Eye in the Sea is basically three separate components. There is the battery which is the power source, the camera that is in an underwater housing which can withstand 3000 feet of water, and then a light, which is red, which is invisible to the animals. The light is just a set of red LED's, and one of the problems we have using red illumination underwater is that red doesn't travel very far underwater, and that is why everything is blue underwater. That is why we also need to use a specially intensified camera to make up for that fact. The rest of it is the frame which you see here. These things, which look like they are rocket launchers, are not. They are actually mounts that allow us to hold it on the front of the Johnson Sea Link. There are a couple of prongs that slide into these holes, and when we take it down to the bottom of the ocean, then we slide it off. It's got feet that allow it to sit on muddy or rocky bottoms. Another component that we were testing out there was this electronic jellyfish, which is just a bunch of blue LED's in a circuit that can imitate the flash pattern of a luminescent jellyfish. It was actually this that was going when that 6 foot squid attacked. I'd like to believe that it was attacking this, but unfortunately it was just a little bit out of the frame, which was very frustrating. So at sea, we came up with a solution to that. My graduate student Erica Raymond and Justin Marshall from Australia worked all night one night trying to figure out a way to make this stay in the right location in the frame, and what they came up with was the CLAM, which is the Cannibalized Ladder Alignment System. It was an aluminum ladder that they found on the ship. They attached it to the bottom of the frame and had it hooked up, and when the submersible was at the bottom, the ladder folded down slowly, which let the bait bag and the jellyfish be in perfect view of the camera.


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