Towed sonar was already under development during the First World War. The passage identifies Harvey Hayes, a US Navy physicist, and an early system called the Electric Eel. It says the work was discontinued after the conflict and not resumed until the 1960s. The counterfactual is specific: sustained Royal Navy and US Navy development might have matured the technology earlier and mitigated some limitations associated with ASDIC.
Notable Point · 2:12:01-2:13:21
The First World War origins of towed sonar
A technology aside traces an early American towed-sonar system to the First World War and asks what continued interwar development might have done for ASW.