[TorpX]

Originally Posted by dreadedlyfe

let me start off by stating that this makes sense to me, but i am full tilt boogie on my pain pills. ...

here is what i have rattling around in my head. say you have a contact(s) and your watch was awake so you picked him up early instead of a snapshot situation. you are able to get a speed and coarse. all of this should be able to be completed without raising the scope for a peek. you should be able to watch the plot for your target to cross the shoot bearing. if you held your nose right, then you get get fireworks at the end.

when you do your 3 minute plot, you have all three things that are needed. if you extrapolate the 3 minute plot you should, in theory, be able to plot out a predictive path over time. as the contact travels through the time aspect, which is the only constant, if the contact changes direction or speed, then you should know ahead of time. on the flip side you should be able to fire on the target using the ships chronometer.

it might be watching the clock versus the plot, but it is the predictive part that seems important to me. idk. at any rate, im sorry if this isn't making sense and if it isn't right, let me know.

I'm still not sure what it is you want to accomplish here.

If you are talking about making visual/radar observations, and then submerging to make the attack, this is certainly possible, but to what end? It was generally considered neccessary (or at least highly desirable), to visually confirm hit and sinkings.

If you are talking about making a sonar only approach. This is theoretically possible, but difficult in practice. Sonar only approaches were taught in the USN before the outbreak of war, but quickly abandoned in the early months of the war. To have any real prospect of obtaining a good set-up and firing solution, without visual/radar data, you would need to ping the target repeatedly, which is more of a givaway than using a periscope would be. I'm sure some have done this and sank a few ships in this sort of way, but in ordinary circumstances, this would be going about things the hard way.