Chummy ship

Chummy ship: A naval expression when the Ship's Company of one ship in a fleet or squadron is on specially friendly terms with that of another. Each ship would be the "Chummy Ship" of the other. On a foreign squadron visiting British ports, as on the occasion of a Naval Review, those on board certain British ships are told to see the entertainment of the Ship's Companies of corresponding ships of the visitors, and the ships become chummy ships.