Hurried River-class conversions would be a poor way to fill the gap before Type 31 frigates enter service. The general-purpose Type 23s already possess the hull, sensors, combat systems, and survivability for a higher-threat role, so retaining suitable ships is the more coherent bridge. A River upgrade would require new weapons, cabling, radar integration, command-system work, and months out of service, potentially finishing only as the Type 31s arrive. Batch 2 Rivers already provide useful low-level capability through a Merlin-capable flight deck, embarked personnel, boats, and the option of a telescopic hangar. Keeping them on presence missions while extending viable Type 23s avoids creating two simultaneous availability gaps.
Notable Point · 3:18:22-3:24:25
Retaining Type 23s beats converting Rivers for the frigate gap
If Type 31s are late, extending suitable Type 23s preserves real frigate capability more effectively than taking River OPVs offline for complex upgrades.