Calculation of firing by volley of torpedoes

[Pisces]

Or if he is numbercrunching inclined:

1 degree is 17.5 meters wide at 1km range. 17.5 meters is 0.5 degrees wide at 2km. (twice as far=halve of the angle) So 35 meters wide is 2 degrees at 1km, or 1 degree at 2km. (twice as long at distance, is twice the angle at that distance)

This is useful if you know the target length, and it is showing 90 degrees AOB. But if not then it requires further reduction based on AOB:

10 degrees AOB (or 170), 17% of the original length,
15 degrees AOB (or 165), a quarter (26%) of the original length,
30 degrees AOB (or 150), halve (50%) % of the original length,
45 degrees AOB (or 135), 70% of the original length,
60 degrees AOB (or 120), 85% of the original length,
75 degrees AOB (or 105), 96% of the original length.