of a ship is its width at the widest point, or at the mid-point of its length. Generally speaking, the wider the beam of a ship (or boat), the more initial stability
it has, at expense of reserve stability
in the event of a capsize, where more energy is required to right the vessel from its inverted position. Typical length-to-beam ratios for small sailboats are from 2:1 (dinghies to trailerable sailboats around ) to 5:1 (racing sailboats over ). Large ships have widely varying beam ratios, some as large as 20:1. Rowing shells
designed for flatwater racing may have length to beam ratios as high as 30:1 , while a coracle
has a ratio of almost 1:1 - it is nearly circular.
- Hayler, William B.; Keever, John M. (2003). American Merchant Seaman's Manual. Cornell Maritime Pr.
- Turpin, Edward A.; McEwen, William A. (1980). Merchant Marine Officers' Handbook. 4th, Centreville, MD: Cornell Maritime Press.