Manual Plotting Hints and Tips

Determining Target Speed via Mark One Eyeball

don1reed on Subsim posted the following formula, which you can use to determine a target’s speed fairly accurately:

Ship's length past the vertical graticule / seconds x (3600/1852) = speed.

The bearing to your submarine from the targeted ship, your AOB, must be between 60 and 120 degrees. You should be at full stop for best results.

don1reed provided a quick example: i.e., T2 = 152.7m / 40 sec. x 1.94 = 7.4 kts.

Also see: Target speed calculation made easy

Determining Target Course with Weapons Officer

Supplied by Gipodiablo on the Subsim forums.

If the target’s AoB is starboard, here’s the formula:

180 - AoB + Your Ship's Heading + Your Ship's Bearing to Target in Periscope

If the target’s AoB is port, here’s the formula:

AoB - 180 + Your Ship's Heading + Your Ship's Bearing to Target in Periscope

If your result for either formula is greater than 360, you need to subtract 360 from the result.
You’ll need to click the compass as close to your current heading as possible and use the number reported to you by your navigation officer.