Sag (Sagging)

The condition of a vessel caused by the unequal distribution of cargo. When a vessel loads too heavily in the center it causes a bending downward of the hull at the midships area. This can also be caused by the vessel working in heavy seas with large waves under each end and no support under the center of the ship. Sag is the opposite of Hog.

In seamanship, SAGGING to leeward, signifies the movement by which a ship makes considerable leeway, or is driven far to leeward of the course on which she apparently sails. But as a phrase applied to the hull of the ship is the very reverse of HOGGING, as then the midship part of the ship by straining arches upwards, whereas in sagging, by a different sort of strain, it curves downwards.