Felixstowe flying boats and the Spider's Web patrol

Curtiss-derived flying boats offered the endurance needed to cover large sea areas from dawn to dusk. The Spider's Web patrol traced a repeatable search pattern over the Channel approaches, contributing to the wider barrier system. Airships could search from high altitude but were less able to pressure a submarine or go where the patrol was needed. A flying boat's greatest value was often denial: it could force a U-boat down, while even slight damage might trap the boat on the surface and leave it vulnerable to destroyers and weather.