Protect your vessels and set up anti-air defences with the new Barrage Balloons!
As airpower grew in strength as the war progressed, the world’s navies used any and all devices to keep strike aircraft away from their shipping, whether large or small, naval or merchantmen. The humble barrage balloon, a gas-filled bag secured by a stout steel cable and floating perhaps a few hundred feet above the craft, was common to most navies and helped deter either low flying torpedo attacks or as often, dive bombers. Simply put, they spooked attacking pilots who feared to lose a wing in a collision with the steel cable hovering over the target ship.
Photos of the Allied fleet at D-Day show hundreds of these bloated gasbags suspended over the fleet as protection against the Luftwaffe. As the Luftwaffe was incapable of serious day attacks, they were taken down as they, in fact, made a great aiming point for German artillery ranging! They were cheap and relatively effective; discouraging pilots from pressing home an attack.