Death Roll

In a keel boat, a death roll is the act of broaching to windward, putting the spinnaker pole into the water and causing a crash-gybe of the boom and mainsail, which sweep across the deck and plunge down into the water. The Death Roll often results in destruction of the spinnaker pole and sometimes even demasting of the boat. Serious injury to crew is possible due to the swift and uncontrolled action of the boom and associated gear sweeping across the boat and crashing to the (now) leeward side.

For dinghy sailors, a death roll is a common type of oscillation while running downwind. It may, and often will, result in a capsize if the skipper does not take quick action to prevent one.

During a death roll, the boat rolls from side to side, becoming gradually more unstable until either it capsizes or the skipper reacts correctly to prevent it. While on the dead run, off the wind, the force exerted by the sail lies almost parallel to the center line of the boat. There is little or no force causing the boat to heel to leeward, unlike most other points of sailing, and, if the sail is out past perpendicular to the center line, or the sail is incorrectly shaped, there may be a force causing the boat to heel to windward. Instabilities in the wind, and turbulence caused by the sail, which 'fouls' the wind on such a tack, may cause this force to change rapidly. Most sailors also retract the centerboards of their dinghies while on the run, to reduce drag and increase speed. The lack of resistance to the rolling motion can enhance it.