A network of defended ports could give merchant ships protected points along their routes. Aircraft based at coastal and island positions would search the surrounding waters. Surface raiders would face a harder task if merchant shipping could move between defended locations. A submarine surfacing near a port could also face radar-directed fire from 6-inch or 9.2-inch coastal guns.
Notable Point · 1:47:06-1:48:24
Fortified route nodes against raiders and submarines
A chain of garrisoned ports, air-search bases, and coastal guns could give merchant shipping protected stepping stones while making surface-raider and submarine patrols more dangerous.