This type IXU is shown running on the surface at night, using her diesel engines to recharge the batteries for her electric motors. The bright moonlight makes this a risky business. Boats would much rather run on the surface in fog, or low cloud, making them much harder for enemy aircraft to detect. With the advent of improved airborne radar, even such natural 'cover' would provide scant protection. Not until the introduction of the snorkel breathing tube would U boats be able to recharge their batteries by running the diesel engines whilst still submerged. Even this was not totally safe, as the snorkel head, being above water, could be detected by radar, and special anti radar coatings were developed. This boats gun crews are closed up and her bridge watch keeps an anxious eye on the skies as the recharging continues. The boat shows considerable wear and tear from her sortie into the storm wracked waters of the mid-Atlantic.