diepgang

Diepgang is a nautical term used in Dutch to denote the depth of water a vessel requires to float, commonly translated as draft or draught. It is the vertical distance from the waterline to the lowest point of the hull that is submerged. Diepgang varies with loading, ballast, trim, and hull design; a heavier vessel, or one carrying cargo, exhibits a larger diepgang, while discharging ballast or reducing load reduces it. It is typically expressed in meters or decimeters and is recorded in a vessel’s line plan and operating documents as the ship’s draft and as the maximum permissible diepgang for specific routes.

Operationally, diepgang determines whether a ship can pass through channels, harbors, locks, and under bridges. Port authorities publish maximum diepgang for waterways, and pilots or masters calculate the expected diepgang on arrival by considering current load and trim. If the expected diepgang would exceed allowable limits, the voyage may require lightening of cargo, ballast adjustment, or rerouting.

Diepgang is also used metaphorically in Dutch to denote depth or profundity of content, analysis, or argument; a topic with substantial diepgang is considered to have significant substance or complexity.

In German-language sources the nautical equivalent is Tiefgang, while English uses draft or draught. See also: Draft (nautical), Waterline, Keel, Ballast.