HMS Venturer (P68)-- Part 4: A Real Good Guess

The Venturer, however, only had eight torpedoes as opposed to the 22 carried by the U-864.  After three hours of the cat-and-mouse, Lt. Launders decided to make a prediction about the U-boat's zig-zag and he released four of his eight torpedoes at what he figured would be its new course.

Now, I don't understand this, but will give it anyway:

This manual computation of a firing solution against a  three-dimensionally maneuvering target was the first occasion in which techniques were used and became the basis of modern computer-based torpedo targeting systems.  Prior to this, no target had been sunk by torpedo where the firing ship had to consider the target's position in three-dimensional terms, where the depth of the target  was variable and not a fixed value.

I'm guessing all this means that not only did Lt, Launders have to guess which direction the U-boat would go, but also how deep it would be running.

--GreGen