TWOS Attack Disc confusion

[UTurnBoat]

Ahoy, captains :Kaleun_Salute:

I've recently returned from a long hiatus to SH5 and immediately installed TWOS to complete the immersion, while I'm over the moon with the amount of additives, and especially the fine control all the manual stuff gives you still the attack disc confuses me.

I've gone through and searched through all the resources I could find, including the excellent video on the RAOBF and Attack Disc on youtube as well as the handbook from the forums, however one thing simply bothers me to no end and makes me feel as if I'm missing something

Why is the number 180 is on top of the outermost disc? So my submarine heading due north is technically on course 0, and then I spot a freighter 3 degrees to my right, so the bearing is 3, but then on the disc it would be 183? Wouldn't it make more sense to have a 0 on the top?

[Aktungbby]

Ahoy, captains :Kaleun_Salute:
I've recently returned from a long hiatus to SH5 UTurnBoat!:Kaleun_Salute: here at :subsim: a kaleun is oft measured by the length of his hiatus!:shucks: &: feel free to join the "proud SH5 owners" social group,:yeah::arrgh!:https://subsim.com/radioroom/image.php?groupid=2&dateline=1554160981&type=groupthumb

[bstanko6]

Because if the target is opposite your bow it would face 180 degrees. And there are plotting methods that the opposite number comes in handy.

[UTurnBoat]

Because if the target is opposite your bow it would face 180 degrees. And there are plotting methods that the opposite number comes in handy.

So the outer scale isn't as much your boat as much as the angle on bow of the ship you're looking at then? That would make more sense as if they are going opposite of you that would make your boat on a 180 heading relative to them

[derstosstrupp]

The outer scale represents relative bearing. The reason why 180° is at the top is due to how bearing relates to own and target courses on the disc (for most problems, you place own course opposite the white triangle at the 180 mark at top). Please see the video link below where I demonstrate the use of the various pointers using the Sub Buddy app which is faithful to the historical disc. That example is about as complicated as the disc gets and beyond the scope of the game unless you want to simulate a no-TDC shot, but it shows all of the concepts of relative bearing, AOB, lead angle, etc. Hopefully seeing the pointers used correctly will clarify the relationships.

https://drive.google.com/file/d/1sjDbKw5C12oL_bCIyPw_5RJMjMY1fv0z/view?usp=drivesdk

[Rwearjr]

Welcome to SubSim Usettlem!
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