A Commonwealth coast-guard fleet as prewar capacity

Could surplus destroyers become long-range colonial or Commonwealth coast-guard vessels?

Yes; a genuine civil-security role could preserve crews and stimulate replacement construction, while producing more usable escort capacity by the start of war.

Former destroyers and similar craft could serve in coast-guard roles around the Commonwealth until replacement programmes created newer local vessels. The Washington treaty counted British and Commonwealth naval strength together, so simply transferring major warships did not evade the limits; the small ships needed a credible civil-security role and reduced armament. Coast-guard work would preserve crews and machinery while locally funded replacements sustained designers, yards, and engine suppliers around the Empire. By 1939 the original destroyers might be worn out or already replaced, but the programme would still leave trained personnel and a larger pool of ships for anti-submarine and escort work. The proposal builds distributed maritime capacity without creating a hidden imperial battle fleet.