Narrator: This is Science Today. A small unmanned vehicle that travels underwater about half a mile an hour made recent history crossing the Gulf Stream – one of the strongest currents in the world. It's called Spray, and oceanographer Russ Davis of the Scripps Institution of Oceanography at the University of California, San Diego, helped develop it.

Davis: Spray is like a very small submarine, about six feet long. It has little wings that make it look a little bit more like an airplane than most submarines. It drives its way forward through the ocean by going up and down.

Narrator: Every seven hours for fifteen minutes, Spray surfaces to beam its current location to scientists in Massachusetts and San Diego. There, researchers can record information about the ocean's depth, temperature and salt levels.

Davis: Someday when we do this many times, we'll begin to see first the seasonal variations and how it may change from one decade to another, to help us understand how the biology of the ocean is changing as well as the physics.

Narrator: For Science Today, I'm Larissa Branin.