Looming several miles off the starboard bow is Columbia Glacier, dropping icebergs into the sea. Those icebergs can float into the shipping lanes, presenting a navigational hazard to the tankers. But the larger ones seldom do. According to John Denham, an expert in marine accidents who serves as director of continuing education at the California Maritime Academy, inexperienced pilots sometimes overreact to icebergs. The mind's eye tells you that there's this massive thing under water. . . .
Inexperienced pilots have a tendency to overclear that thing.
Turn too far away, Denham says, and the unrelenting momentum of the tanker makes turning back a long, slow process. Of course, Denham says, the pilot needs to know where his ship is in relation to Bligh Reef, the most obvious hazard in the upper Sound. The information's all there. . . . Now whether they use it or not is another thing. Part of the pilot's problem is knowing how the tanker's mass affects its momentum.