Need some advice for manual plotting
 

Howdy folks,

I'm doing better with manual targetting, but there's one thing that I'm still having difficulties with....namely, plotting manually on the NAV MAP to measure speed. I'm using the three minute chronometer method.

Btw, I've tried the Dick O'Kane method, but I've decided I'd rather not use it on a regular basis.

The problem seems to be that it takes me too long to make the actual plot on the map, so with the target still moving, by the time I actually get the plot on the map, the numbers are inaccurate, making my speed calculations too high.

I'm using SH 1.4, with TMO, RSRD, PE2. USS-Sturgeon, early war career, 100% realism....

Here's my typical procedure, so maybe you can tell me if there's a better way:

1. ID target using periscope or TBD.

2. If the seas are choppy, I tend to dive and use sonar instead of the stadimeter to determine range. Trying to use the stadimeter in choppy seas is an exercise in frustration with all the bobbing, especially using the TBD.

3. Manually locate the target using the sonar station, then ping the target 3x using the active sonar, sending the data to the TDC(ala Werner Sobe). Then I enable constant reporting from the sonar operator.

4. Switch to the NAV map and attempt to use the ruler with the tool helper enabled to plot the bearing & range I got from sonar to make the first mark. But by the time I do all the zooming in & out to and moving the NAV map around to keep my sub in the spot I need it, the actual mark I've made has already lost some accuracy. The actual moving of the map around is the most frustrating thing for me. I wish I could "pin" the location of my sub in a particular location on the map, and it would actually stay there, no matter if I zoomed in or out.

Anyways, as soon as I get the first mark plotted, I start the chronometer. When it gets to about 2 mins 45 sec, I go to the sonar station and repeat step 3 again, and then whip back to the NAV map and try to plot the position before the chronometer gets to 3 mins. As you can imagine, more times than not, I end up not getting the plot on the map until the target has travelled another 400 yards or so.

I've tried pausing the game while in the NAV map, but I always seem to want or need to do something in there that can't be done with the game paused.

I could just estimate the speed based on whether the sonarman report it at slow, medium or fast, but I want to be more accurate than that.

Any suggestions are appreciated.

I agree there are certain limitations to the map and tools. When you see the pro's do it they do make it look easy. Getting the speed correct is paramount and the most difficult part for me. With experience you can get approximations which you can confirm with a good plot.

I do not have an answer except to suggest, pausing the game and working a plot on paper or electronically on MoBo, I have used both with success.

I also went to a "real" chronometer, got one on ebay used. Very nice and much better to implement than the ingame chrono.

You will have to experiment and come up with your own methods, over time it does get more intuitive.

My favorite is a hydrophone only attack, send parameters to the TDC, plotting course and speed, setting up the boat and then confirming with a 7 second periscope peek and back down. That is very rewarding especially when you get hits. But then again there is that pesky torpedo problem to contend with.....:up:

Happy Hunting!

Nice idea Wilcke about the real chronometer, I might go and get one as the annoying thing for me is the chronometer disappearing when I switch views.

Slick, you can pause time and still plot things on the nav map. That should give you all the time you need. Or, you can do what some skippers did at sea - stop and make it easy.

If you want to sail about and don't want to do a plot relative to your own sub, and keep moving about on the map, you can just pick a spot on the map and do a relative plot there. You'll need to mark the start of your own sub's position when you take your first reading and an end mark when you are ready to get the target's actual track. This way you will end up with two vectors, one is your own sub's movement and the other is the targets relative movement to your sub. You can then add the two vectors together to get the targets plot, but I really wouldn't recommend doing it this way! It's much easier to pause time and plot directly against your own position.

I don't know if it's this way by default, but at least in Trigger Maru the nav map tools can be used while the game is paused. Pause the game, make your plots, resume the game. That will help.

Since I went to manual targeting, I haven't run a boat that didn't have SJ radar on it, so estimating the speed has been very easy for me. Without the radar, I think I'd have to be submerged and use the active sonar to accurately place the ship position.

Yep, that's stock behaviour.

Thanks for the suggestions, guys. I appreciate the replies.

I forgot to add one more problem that rears it's ugly head each time. By using the active sonar to get target range, I typically use three pings each time, sending that data to the TDC. Now then, according to the 3 minute rule, I should be able to stop the chronometer right at 3 mins, then plot the 2nd mark. BUT, it's at this point that I need to record the bearing via the sonar station, and then ping the target three times. By the time I'm done doing all this, it's at least 3.5 mins. So, even when I switch to the NAV map and pause the game, I've already gone over the 3-minute rule by a good 25-30 seconds.

Surely I can't be the only one using this method and experiencing the same frustration?

The pinging three times thing is only to give you the human an average reading, as the sonar gives you fairly but not very accurate readings, so taking three readings allows you to get an average reading. I don't think the TDC gets a more accurate range if you ping and send three times, or even ping three times and send once. In fact, it may make the auto speed thing record ranges that are jumping about and that may make your speed estimate worse.

I think as well that the stop watch auto speed calculater icon knows at what times you sent the readings, so you don't need to do it at exactly 3 minutes. The 3 minutes thing for the speed is for you to work out the speed in knots when plotting in yards - I think it's 3 minutes and 15 seconds or something for meters, haven't really looked at it in great detail. But anyway, the auto speed button only needs a few readings over a period, I dont think it needs precisely timed readings, so you should be able to plot and send to TDC independently. Try it and see what happens.

Edit: OK, I'm getting confused here. Are you trying to plot only by manual plotting, if so why are you sending stuff to the TDC? :hmm:

Ok;

1. At the mark, record the bearing.
2. Switch to Nav Map.
3. Pause
4. Plot
5. Un-pause
6. Go do your pinging.
7. Switch to Nav Map.
8. Pause
9. Plot the distance.

That could be a SOP.

I usualy plot the speed with the stadimeter. I do it severel times durring the Normal Approach Course or Optimum Approach Course from ranges of 7000 yards and in.

This gives you plenty of time to do lots of 3 min checks. I use the circle tool to plot the contacs, having the arrow part showing direction of travel of the target. Say i then have like 5 x 3 min plots over 15 min's i have the option of comparing them, and/or making an average (take the first plot's circle and enlarge it untill the edge of the circle intersects with the center of the last plot - divide the circles diameter with the total time from start plot to end plot and multiply that with 3 and divide with 100.

I have Cource Calculator slide rule next to me. Before starting my plotting i turn the wheel to my own course. From then its easy to very fast get a true to north bearing on the target from the wheel. What i doo is this:

1) NavMap Centered on sub
2) change to Stadimeter - make sure the left side TDC is open on the selection that shows ranges is present.
3) make sure you take the stadimeter range for the correct item (i use funnels) using the correct stadimeter setting (i use the manual input option on the masthead height)
4a) Scope up (All the way so it clears fast)
4b) take a bearing/range and note it on paper fast - estimate AOB
4c) Scope down (only untill its just under water - then stop it)
5) start stopwatch (only the first plot naturaly)
6) NavMap - linetool click on sub fast
7) ease off as from now you have 3 min's to make this plot before the next is up.
8) plot by extracting the line from the sub too the correct range read off the TDC and then i make a 300 ft. circle there. I let the radius arrow in the circle point in the way of travel.

I know the stadimeter is not the most presice tool, but for getting the speed correct in 3 min plots its mighty fine and more precise for us than it was in reality.

That's an interesting method, Mav, I think I'll give that a try. I didn't even realize that there's an arrow on the compass! I'll have to pay closer attention from now on! :lol:

Btw, is there a keystroke in TMO to center the sub in the nav map?

Most people will tell you to do a plot with absolute bearings -i.e. plot starting from your sub icon on the map and keep the plot always from the sub's current position- but I found out long ago it is way easier to do it with relative bearings. Here's how to:

1.- Forget about starting from your sub, and go pick a place in the map where you can work and plot without distractions (An area of only water is ideal)

2.- Start by using vertical ruler to draw a line from bottom to top. This represents your sub's motion forward. Note your sub's speed.

3.- Now, scope up, get range and bearing to target. Start the chrono.

4.- From the initial point of the line you drawed in step 2) and using your ruler, draw a line in the bearing of the target. Use the compass in the tool helper to make it properly (Since the line you drawed is on course zero the compass in the tool helper matches exactly the scope bearing from your sub). Either use the compass in the tools or the ruler markings to make the line reach the proper measured target distance.

5.- 3 minutes later, up scope again and take bearing and range.

6.- First, calculate how much your sub has advanced in those 3 minutes with the easy mental rule. Now go that distance along the vertical line upwards and put a mark there. That's where your sub was when you took the second bearing :) Now pick again the ruler and draw from there the bearing and range to target of your second reading.

7.- Repeat as necessary to get a good speed reading. Serves also to get angle on the bow easily, which you can measure with your angle tool. If you want target's true course, you must add substract that AOB from your true submarine course. That's all.

Advantages:

1.- Simple to use with the game tools

2.- No hurry to plot from where your submarine icon is each moment. You have three full minutes to plot your sub's and the target's new situation each time.

Hope that helps.:up:

Wow, that sounds so elegant, Hitman! :|\\ I'm going to try that right now. Many thanks!

This is all too complicated. Use your Dick'O'kane course/speed plot. Eyeball the intercept. Make a 500yd circle with compass. Get near circle and get to 90 (plus or minus 20degrees) AOB. Make a 0 or 180 straight torp solution. When target gets close enough ID it and set depth if you wish. Down scope. When target gets to edge of your 500yd circle up scope. Fire at 0 + or - your targets speed in degrees. I.e. If hes moving 12kts from right to left on a 0 degree torp course fire at 348 degrees. Even if you're off you are so close you can't miss.

Hey Hitman, I used your method last night, and once I got my head wrapped around it, it worked like a champ! :up:

Cheers slick, glad you found it useful :up: