In sh4 no matter the angle you can hit your target from 270, 180, 90, 0, using the bow tubes. the solution for firing of fish at 270 for example optimal track is to have the target ship at 6 knots and AOB from 90-98 when shooting from the bow tubes and your boat is heading east , you will need to aligin the scope at 270 and set your paramitters .. AOB at 98 , speed at 6knts , the range at 1300 -- you will than align your scope at 260. your torpedo settings , will be contact and speed set at high . you can only allow the Sub speed at 1 knt , once the bow of the ship hits the 260 mark fire at points as the ship passes , the bow , amidships , stern .. this also can be used for the stern tubes ,, I have found out that a 10 degree lead will hit the ship at the 0 spot from were you have aimed , reading Old Is US Navy manuels and practising formulas I have found this works effectivly . Using Manuel targeting is so much more fun .. Since the scope in Sh4 different than SH5 . I had to figure out a way to measure the ships speed using the scope ... Look at fig 1 below.
fig 1
I found out using sh4 scope that if you count the gradients from the stern of the ship to bow of the ship by 5 (scope has to be in the close up view )
you count the stern from the centerline of the scope to the lenght of the ship , multply that by how many marks .. thus if you see 7 mark's, 7 x 5 = 45, 45 x2 = 90 ft you than take the bow of the ship and start your clock and count how many seconds it takes for the centerline to reach the stern. if it took 45 secs than muliply .45x 90 = 40.5 divide that by 3 than you will get your speed 13.5 knts , take this and divide that by 2 and you will get your true speed of 6.75 knts
So far this has been working .. Any suggestions of caculating legnth and speed withSH4 besides the plotting map method would help .. Thanks , happy hunting