For starters, the fact that three people died during their attempt to identify the wreck. The first one, Steve Feldman, became unconscious and was swept away; his body was recovered six months later, but no cause of death could be determined. The second two were a father and son diving team, Chris Rouse and Chris Jr. The son became trapped in the wreck and, running low on oxygen, were unable to find their spare tanks. In desperation, they swam right to the surface without decompressing. The father died upon reaching the surface while his son was airlifted to a hospital, where he soon died as well.
The last third of the episode describes the utter hopelessness that the U-Boat Force faced in the final months of the war.
"The U-Boat Service lost 28,000 dead, and 5,000 captured, out of a total force of perhaps 45 to 48,000 men. A permanent casualty rate of over 70%. No branch of an armed forces has ever sustained these kinds of losses, and kept functioning."
It's not helped by two German submariners recounting the difficulty of the war and hardships they endured, for nothing.
"In spite of the fact that of ten submarines leaving port perhaps two were expected to come back and eight were not, when we left we were absolutely sure we were going to be one of the two which would come home. This of course is a totally irrational approach to the problem, but it helped us go out time and time again."
The epilogue: after the divers contact three of the families on the real fate of their loved ones, there's a brief interview with the only survivor of U-869, who was hospitalized just before the boat left.
In particular, one of the family members lived in Maryland, not too far from where her brother's boat had sunk. She is moved to tears at learning that he had been so close all this time.
