Definitely, it can easily be done on the map:
1. Draw a line toward the “target”.
2. From that line draw a line at the angle of the AOB you intend to shoot at (50 in this case). Make the length of that line equal to the target speed, in this case 15 kn.
3. Draw a line of a length equal to the torpedo speed from the starting point, 30 knots in this case.
4. Move the target speed line down and adjust the torpedo line til their ends meet. Do not change the lengths of the target and torpedo lines though!
5. The lead angle will be the angle at the starting point (22.5 here).
