The communication problem for undersea drone swarms

When could Britain and the United States field reliable submarine-drone swarms?

Not soon, because underwater communication and control remain the fundamental technological barriers.

Vehicle construction is easier than the command-and-control problem. Navies can already build small uncrewed submarines and extra-large uncrewed undersea vehicles. Water severely restricts reliable communication, making a tightly coordinated offensive swarm much harder than a collection of individual drones. Designers must then decide how much autonomy to place aboard each vehicle when contact is intermittent or lost. The barrier is therefore trusted control and underwater networking rather than the basic hull technology.