waterline length , LWL (abbreviation)

Generally called Froudes Law, for non-planing, non hydrofoil boats there is a relationship between maximum speed and the square root of the water line length.

The required inputs are the average areal density of icebergs, the average iceberg water line length, and the average iceberg drift velocity.

Because of the hull configuration, at a substantial angle of heel, it is similar to having a catamaran on one hull: the ratio of water line length to breadth increases dramatically, along with a geometric increase in speed.