The Arethusa class was intended as a small but viable cruiser for trade-route duties. The Royal Navy hoped that six ships could fit within the tonnage allowance needed for five Leanders. The pressure came from cumulative treaty limits: an individually capable 10,000-ton design could still leave too few cruisers to cover the required stations. A hoped-for 5,000-ton ship offered twice as many hulls within the same allowance, although the actual standard displacement was higher. The hull also offered a basis for the Dido design with a different gun battery.
Notable Point · 4:15:28-4:18:26
Arethusa-class cruisers and fleet quantity
Cumulative treaty limits made small cruisers attractive when the fleet needed enough ships to cover many duties.