Dry-dock inspection could expose treaty-breaking cruisers

How could navies tell that a rival's cruiser exceeded Washington Naval Treaty limits?

Close inspection of hull form and waterline, especially in a foreign dry dock, could reveal that the declared displacement was implausible.

Treaty displacement could not be hidden perfectly whenever another power gained close access to a ship. Hull dimensions out of the water, combined with the normal waterline, allowed constructors to estimate displacement. An Italian heavy cruiser repaired at Gibraltar gave British specialists enough information to judge quickly that the ship could not be within the nominal limit. Compliance therefore depended partly on avoiding revealing inspections as well as on official declarations.