A tender is a floating repair base

A tender concentrated the workshops, stores, accommodation, cranes, and skilled personnel needed to keep aircraft operating. Seaplanes repeatedly entered salt water and could require more maintenance than aircraft operating from a carrier deck. The tender used the surrounding harbor as its airfield and could devote substantial internal space to workshops and boxed aircraft. A slow merchant-type hull, smaller engines, and cranes in place of aircraft lifts kept the ship simpler than a carrier. Its machine tools were similar to equipment already produced for factories and naval workshops, while its aircraft technicians would also have been required at a shore base. These facilities still had a cost, but the proposal did not require inventing an entirely new industrial or personnel establishment.