Why Bay Area athletes are chasing container ships, at great peril

Surfing the industrial-size waves of a giant ship in San Francisco Bay is a thrilling experience: smooth, silent and sublimely fast.

It can also be extraordinarily dangerous. And illegal.

“The ship can suck you in, drag you under and chop you up like a Cuisinart,” said David Wells of the San Francisco Boardsailing Association, which has started an educational campaign to prevent tragedy in those who venture too close.

Bay Area athletes have long loved extreme water sports...