[greyrider]

the reason why i think this could work so well at very long range is because at long range the aob is going to be very small, less than 10°, and that would be the best time to make the calculation, and once the speed of the target is known, or approximated, matching up bearings to target at
the speed you calculated should bring you very close to the targets relative course, over time. but speed is more important than course here, because even if your playing auto tdc, once target direction has been established, its very easy to drive your sub into a 90 target track angle.

in the formula test mission thats now up on my filefront page, if you try it, use a target aob of 20° in the formula, i think i kept the target bearing constant at bearing 291°, and own ship speed of 5 knots,
the target speed in the formula test mission is 12 knots, lead angle was upper 60's, cant quite remember because i took subsequent readings also, as the aob got deeper.
in my estimation, the hydrophone max range in sh4 is 18.9nm. even in the formula test mission, at 9nm, the target aob was only 20°, or near 20°, so i would be looking for a very small aob at long range, it could even be less than 10° at that range.

anyway
target speed is the mission is 12 knots
sub speed was 5 knots, when the bearing of the target changed, i increased or decreased speed to keep the bearing constant, i took other readings as the aob increased, to test my estimation of aob by hydrophones.
lead angle is from the bow of the sub to the bearing of the target.
what skill needs to be developed is estimating aob by sound, target diection is easy, but finding a number for aob might and is alittle harder but not impossible, even if target speed is off by a knot or 2, estimating the time of arrival
at your calculated speed into your visual ao, would tell you if your speed calculation is accurate or not, if target arrives too early( earlier than your estimation), its going alittle faster than your calculated speed, the reverse if its arrives later than you thought it would
theres always ways around things, we just need to always be flexible in our thinking, and make adjustments if we have to.

if i learned anything from sh about sub warfare, its that precision is not mandatory,
just being close is good enough, in most of the data we need except for speed, that has to be pretty close to precise.