For his geography homework, my son recently had to read up on the 1989 Exxon Valdez oil spill. As a shipping journalist, I had extra knowledge to offer him: While the incident was an environmental catastrophe, the legislative response helped reshape tanker shipping. Over time, the phase-out of single-hull tankers eventually made such disastrous spills a comparatively rare occurrence.

Eric Martin is news editor at TradeWinds.