Deep Dives
June 21, 2000, p.m.

	Guy Cochrane in DeepWorker Photograph by Kip Evans

It's over the side and into deep water today for Guy Cochrane, SSE's geologist-pilot from the U. S Geological Survey. Guy's goal, ground truthing data acquired acoustically during the past week using a side scan sonar system, is now being realized. Using DeepWorker's digital video camera, Cochrane records the terrain— and the creatures who live along his transects— straight line sections of the sea floor that he has imaged with sonar and now wants to observe directly. Already he has discovered that some of the images he thought were rock based on the side scan records actually are sand ridges. Based on his on-site observations, he can now more accurately interpret the remotely-gathered sonar images.

	Tracking DeepWorker Photograph by Kip Evans

Today, he is underwater for nearly four hours and travels to a depth of 492 feet [150 meters]—his deepest dive so far. This marks his fifth dive this season, “the best yet.” Not only has he been deeper and seen more variety than on previous dives, but, as he says, “It takes a few dives in DeepWorker to begin to use the systems most effectively. This time, I felt really comfortable, and knew right where to reach when I wanted to check on something.”

Like driving a car or riding a bicycle, piloting DeepWorker is basically simple, but experience pays. Last year, more than 90 people had a chance to use the sub for training dives, but most had brief excursions in shallow water. This year, for best results, we have decided to have fewer people make more and longer dives in fewer places. Already, the strategy is paying off for Guy Cochrane - and for insights that we are hoping to gain about the ocean.

— Sylvia A. Earle
Project Director
Sustainable Seas Expeditions

[Note: nationalgeographic.com does not research or copyedit dispatches.]