SUBSIM Radio Room Forums - Mission Feedback

Hello All,

Just wanted to share an experience I recently had and get opinions and feedback based on it.

I just completed the mission Aloha. The premise is there is a Xia and at least one escort sub right off the coast of the northern coast of Hawaii. You are in a 688i and tasked to sink them.

Right off the bat, as soon as the mission started, I streamed the TA to about 1/3 length and went to periscope to check the ESM and radio. Couple merchants around me and some whales (found via broadband).

I then go down to ~350 ft and scan around using the narrowband on the TA. Doesn't take long, I soon see a 50 Hz line and the filter is saying Han. I assume this is at least of the Xia's escorts. I confirm it is a Han by checking the sonar sheet and comparing the high frequency lines. I eliminate any ambiguity in the TA by checking the same bearing on the bow array as well.

Next phase is to try to determine if I am on a lead, overlead, or lag course with the Han. After ~ 6 to 8 minutes I determine I must be overlead or lag (bearing lines are making x's). I do a 150 degree turn from my current course to be completely sure. The new intercept point of the bearing lines is closer which means I must have been on a overlead course and am now on a lag course.

This is the position I want to fire from. For reference, my course (now lagging with respect to my target) is ~ 155 degrees. I keep the course and get more bearings lines. I start to line up my dot stack. I try the solution and check Truth. I'm about 1500 yards off. Not bad. I fire a torp out of my port tubes and set to enable at 75% range. The Han speeds up when the torp is 60% the way there. A few minutes later I lose the wire and the water saturates. Not bad, though I did check Truth to be double sure (still very much a learner).

Now for the Xia, possibly more escorts. As the water is saturated I kick the rpms up to Standard to hurry through a turn as I make my course ~ 345 degrees. The water begins to quiet out just as my turn finishes and I go back down to patrol speed (3 kts). I start scanning and pick up another 50 Hz line. I compare the frequency lines to my sonar sheet and determine it is the Xia.

As my TA bearing lines start to come in in I try to determine what type of course I am on. Appears to be overlead or lag. I make a 180 degree course change and see that I am now leading him with relatively constant spacing between each bearing line, no intersections. Must now be on an approximately parallel path. I turn back to my original bearing, satisfied that I must now be on a lag course with the target. I wait ~ 20 minutes, playing with bearing lines and trying to determine course.

Now, I start checking truth and compare it to my solutions. What I find is, I get the most accurate solution with the 2 hour dot stack. However, the 2 hour stack is very sensitive to the speed of the target. The Xia has, for whatever reason, ramped up and down several times between 6 and 15 knots. No idea why. But his average speed over the entire time I have tracked him is closer to 6 knots. My 2 hour solution is garbage (over 5 nm past the actual target, down the same bearing) if I used his current demon speed (could be anywhere between 6 and 12 knots) but if i used his average speed, approximately 6 knots by my guesstimation (and help from truth) I got solutions within 2 nms.

So, 10 minute dot stocks with his immediate speed didn't yield as accurate a solution as the 2 hour dot stack with average speed. Something for me to think about.

Without truth to help me gauge solutions and somewhat guess his average speed was lower than I might otherwise would have thought, I probably would have missed. But then again, that is what practice is for.

Let me know what you think fellow submariners! :Kaleun_Cheers: (for reference I am a virtual submariner only :03:)