The longest dimension sets docking and canal limits. Length overall is the maximum length of a ship measured from the foremost point of the bow to the aftermost point of the stern, including projections.

Length overall differs from length between perpendiculars and waterline length, which are used in hydrostatic calculations. Port berths, locks, and shipyards quote limits in length overall. A ship that exceeds the limit cannot enter, regardless of its other dimensions.

Designers and operators watch length overall when planning newbuilds for specific trades. Even small extensions—such as a bulbous bow or stern platform—can affect the measured overall length and therefore operational access.

• Maximum length of a ship from bow to stern
• Includes all permanent projections
• Used for berth, lock, and canal restrictions
• Distinct from other naval-architecture length measures