4 BEARING QUERY

[THEBERBSTER]

Hi Guys
I am doing the 4 bearing tutorial hydrophone only as per Stoianm/Kuikueg not Trevally's True Bearing Method. I wonder if you can answer a question for me.
Calculated bearings 1-87 2-97 3-117 5th mark to contact heading line. Moved my uboat a distance to near 90 degrees of this line. Dived at 30 minutes 4th bearing 18 degrees contact moving away. Is this now a lost cause? If not how should I proceed?
The crew status from Poor to Elite in the tutorial selection what effect does that have in the tutorial?

[Pisces]

I think you moved to the target track too soon. Go parallel to the target track first, after getting the 3 bearings. Based on those bearings you gave, he had a approximate AOB at bearing 1 of 21-28, by the time of bearing 3 it increased to 51-58. If you keep going in the same direction he is going (doesn't even need to be high speed) then you won't give up your forward position. (unless you do it submerged) Only when you have the 4th bearing line, and you know at what distance he is and what speed, should you consider closing the distance/intercept, and place yourself ahead.

Immediately going to 90 degrees across the target track might put you into his rear by the time you get there. Or worse, in his detection range!

Keep in mind! He moves along the track, but you are not because you go 90 degrees across it. Maybe you get lucky and he is slow, but why give up the good advanced position and element of stealth.

[THEBERBSTER]

Hi Pisces
Thank you for your reply. I am confused by the 4th bearing. Stoiamn in his videos refers to the 4th line and also the bearing taken from the uboat after it has moved as the 4th bearing.
I will take on board your advice.

[Pisces]

Yes, that 4th/5th bearing deal is a bit confusing. It is a imaginary bearing drawn from the initial listening location that is projected forward based on the movement of the first 3 real bearings. The 'real' 4th bearing would be the 4th once you reach the new position. Basically you are trying to cross the imaginary bearing line with a true bearing line from a different vantagepoint. You can call this the 5th if you wish. But the important thing is that one is an imaginary bearing (that you'll never be able to listen along), and the real one from the different vantage point confirms the position along the imaginary bearing line.