 "U-3519" was a brand new, high technology electric boat which could run constantly submerged rather than having to surface to recharge her batteries every day the way submarines until that point had had to do.However, these advanced vessels were introduced to the "Kriegsmarine" only late in 1944, much too late to influence the Battle of the Atlantic, and too late for many of them to serve in an offensive capacity at all.With the end of the war near, training on U-boats had dropped to a minimum due to lack of fuel, falling morale and the effectiveness of allied attacks on U-boat construction and preparation.