We tagged 40 white sharks this past fall along the coast of Northern California between Tomales Bay and Ano Nuevo Island. I'm currently analyzing data from one of those tags.

The shark that carried this tag swam to Hawaii, where it hung out for nearly four months -- March to July 2006 -- and then returned to the exact location where we tagged it. That's an 2300 miles each way!

The tags record the temperature, depth, and light every 30 seconds. The tags are programmed to break free, float to the surface and send a signal to our computers via satellite. We try and time the release so that they are back near the coast, and we can retrieve the tag. We got this one!

The tags send summaries of each day they were attached to the shark. But they also have that minute-by-minute data, and we want that. So we take a boat out to find the tags. Now that we know the sharks are returning to their spots so predictably we are setting up on-site receivers where we can automatically monitor their comings and goings.