A valid use of high school geometry!

[ronbrewer]

I'm sure a lot of U-boat skippers out there already know this or have their own systems for closing in on a target with a perpendicular course, but this was a frustrating problem for me early on after going through Wazoo's excellent tutorial on manual targeting. What I found was after getting the target's course/speed and getting way ahead on an end around, once I made the 90 degree turn to get on a perpendicular course I had to halfway guess or eyeball how far to come in before cutting the engines and going to periscope depth. Usually as the target got close I had to back up or go forward to adjust at the last moment.

What I found out after going back over some right angle stuff, that was taught in high school (early 80's for me), is that the cosine of 60 degrees is 0.5 and means that whatever the range is at that moment in the periscope will be the double of the range at 0 degrees. I tested this to make sure the game follows this principle and it's been working out great for all my recent shots. I had a Small Merchant show a range of 1300 meters when the periscope was at 60 degrees (I was on its port side, 300 degrees if I were starboard) and so I went ahead and entered 650 meters for the range and let the torp fly at 0 degrees. I ended up with a shot right at the middle of the ship. Now, coupling this with Wazoo's instructions on getting the AoB ahead of time makes for a less rushed last few minutes of the hunt. This has helped out a lot in rough seas where the waves cause you to lose your lock and you constantly have to keep relocking the target. With the speed, AoB, and range preset, you only have to wait for the gyro to reach zero.