Parametric rolling has been the cause of some very heavy losses of containers over the last years, of which the APL China’s loss of containers in 1998 seems to be the classic case.

Parametric rolling is a resonance phenomenon. It may occur in a head sea with an unfavorable combination of wave height, length, and period in relation to the ship. Sudden extreme rolls may occur without warning, leading to container stacks toppling over, like dominos, causing severe losses.

Larger ships are less susceptible to parametric rolling, except in very extreme weather conditions. Smaller ships, however, may be at peril in more frequently occurring weather conditions. The trading route from Northern Europe to North America is the most likely location for parametric rolling for smaller Panamax ships. The heading distribution in relation to the weather direction is more evenly distributed, including a lot of head-sea conditions. This is due to the predominant weather direction and the fact that the crossing is much shorter than that of the Pacific (5–7 days), giving less room for maneuvering between the cyclones.

Increased awareness among seafarers seemed to have curbed the number of incidents but more research and attention to this problem may still be required. DNV won the Seatrade award for IT innovation in 2002 for a system called Active Operator Guidance (AOG), which is an advance warning system to advise the bridge about rough weather and extreme motions. The know-how from the AOG project has made DNV an industry expert on parametric rolling.