[TorpX]

Originally Posted by LCQ_SH

Are you saying then that while being at periscope depth, we are supposed to always calculate the AOB by eyeballing it?

This was the most often used method.



In the game, people often use the plot to determine AOB, but this wasn't really done in RL. I'll explain why.

The determination of AOB by plot only works if the plot is very accurate. The plot can only be useful in this way, if the range estimations are accurate. Generally, this was not the case. Even if you have a Radar plot, this would have been of limited value, as it would tell you more about where the target has been, than where it is going. In RL, ships zigged frequently, and by the time this could be fully developed in a plot, the next zig was likely to be at hand. [Base course was determined by plot, but this was not what we require for a firing solution.]

For these reasons, 'seaman's eye' was the usual method. There were also tools like Cap'nScurvy's omnimeter, or the prism mechanism in the periscopes, used to measure apparent target length, which permits calculation of AOB, provided the target's actual length is known (often it wasn't).

To put it in concise terms, the AOB was used to inform the plot, not the other way around. WWII sub skippers understood very well they had to be able to estimate AOB's, and the successful ones were probably good at doing so.