Sub Skipper's Bag of Tricks

[Rockin Robbins]

Generally, I'll allocate two per target, one a quarter of the way back from the bow or aimed at the first crane and the second a quarter of the way forward of the stern or at the aft crane. If that doesn't sink 'em it stops them to be mopped up later.

[ichso]

Hi,
I think you all know the problem of setting up an attack when your target is still far away. AoB can be estimated roughly at best and therefore the ship's course also.
Without radar for long distance range estimation you would usually have to get pretty close (something about medium range) before you can make any precise assumptions about your target's movement. Here is a little workaround, that will allows one to estimate the target course when it is still far away. It's more like a little trick than a complex technique so it might be well known already. But let's start:

I got in front of the little convoy to do the rest of the approach from beneath the surface. The approach was already on the way for ~20min now.


First thing to do is to mark your own position on some empty spot on the map and use it as starting point for your observations.

Keep course, take a reading of the ship's bearing (don't forget to calculate true bearing from that) and draw a line from your position onwards in the direction of the true bearing to target. The length doesn't matter as we don't know the range to the ship yet.

From all the previous observations when getting in front of your target on the surface or from using passive sonar you should have already gotten an idea how fast the ship is traveling. Then you approximate it's speed which is mostly a thing of experience values here.
You should be able to tell whether it is moving at fast, medium or slow speed. But what that means for the actual ship depends on your judgement. A slow moving passenger/freighter convoy for instance, I would estimate as ~6.5kn from my previous experiences, so I'm using this value here.

You then wait a fixed period of time. In this example I'm using 5 minutes.
Use the stopwatch and after this time expired let the stopwatch keep running. Otherwise you won't be able to continue tracking your own movements afterwards.
While doing this there's enough time to estimate and draw you position after 5min. Here I'm moving at slow speed underwater = ~1kn, meaning that I will travel ~150y (heading south).

When the 5min have passed, take the second reading and draw another line only now originating from your new position.

So far nothing new. What I'm gonna use now is the fact that the target's speed will have it travel ~1100 yards during this time. See the nomograph on the right for this.
Now, with both bearing lines in place you only need to pick *any* spot on the first line and draw a line that will end on the second bearing line and has the lengh of 1100y.

Note that the first spot you picked there is most likely not the actual position of the target (relative to yours) because we don't make any attempt to get the range yet. The only thing that's important here is that the speed estimation is roughly correct. (And that your drawings are o.k. of course ).
But after encountering many many freighters at a speed of ~6.5kn (when moving at slow) you would accept this as a reasonable base for these estimations.

Here is an image of my in-game nav map to show what I mean.


The small line with length 150y is the way I travelled during those 5 mins and the lower circle shows the spot I picked arbitrarily for the target ship.
The target's course line reads something like 310° and when the vessel gets close enough to do a reliable range estimation you can draw it's real course line (relative to your position at least).

Knowing the course allows you to position yourself precisely, set a course perpendicular to the one of your target (for fast 90 or dick o kane).
Also the target AoB is then only one step away, especially when using an AoB-wheel.

Hope it's not all old news, just figured it might be helpful in some situations.

happy sailing

[Rockin Robbins]

Neat application for optical course determination. I might figure out a possible range of course, say from a convoy speed of seven knots to four or five knots. This would yield two possible convoy courses. Maneuvering yourself to take advantage of either, the real position compared to the two possibilities will allow you to refine your convoy's speed.

[swmicros]

Very good ichso, nice explanation. I have watched and studied the many tutorials on 100% realism but they (at least the ones I have discovered) all deal with the short range final delivery, not the long range approach. I could not figure out a reliable way to predict the target's course. I will definately try this out. (been schooled again!)

[Rockin Robbins]

I still say the "realism" and "map updates off" cannot be rightly put in the same sentence. The game's rendering of map updates off corresponds to driving your car with a paper bag over your head. It may be possible. It definitely would demonstrate great skill. But there is no realism there.

Real sub captains did not pause during the attack, go below to a blank chart and work out the entire solution themselves. Their radar gave MUCH more precise ranges than our radar screen without map updates. As a matter of fact, it was more accurate than when we have map updates ON because they had a digital range readout.

They also had many tools we do not have to work out solutions, bearing rate charts and plots, stadimeter plots, lots of specialized slide rules. We don't have the resources to be able to single-handedly run a plot and call it realism. Check out the Submarine Torpedo Fire Control Manual and see what realism looks like. It ain't our game with map updates off.

It is true that the stock plotting system, while great for learing the ropes, gives the captain WAY too much information. But that is not a decent rationale for tossing the whole thing overboard. The TMO plotting system is the best we have at rendering appropriately selected information without providing "cheats." The only exception is the hardwired too-perfect rendering of positions of visual targets. If you just don't measure from them you'll be fine.

Hope SH5 does better!

[ichso]

I believe you, RR.
But so far I don't own a radar on my boat, so drawing very unprecise lines might be a bit more realistic than if I had one .

I think I don't play for realism at this point when drawing all the map contacts by myself. It's mostly for what feels the best or most realistic or whatever. I just like to see stuff on the radar or through the scope and then work out the map overview by myself. Has a touch of 'bringing it all together' or however one might describe it.

It is also a matter of what specific part of the submarine theme you want to be simulated. If you turn map contacts on you play more of a skipper's view where you only have to make your judgements based on the already evaluated information.
My approach is a bit more crew-based, probably. If someone's job on the crew is drawing map contacts than I simulate it by doing it myself. But when drawing I don't play the captain anymore I play the navigator or some other officer at this point. Both ways have their own appeal to them.

But something in between satellite guided, realtime updated maps and drawing unprecise line based on unprecise estimations and readings would be great, that's true .

By the way, what is it that TMO does to provide less cheated information ? I only really used RFB so far. Maybe I try a switch for comparison.

[Rockin Robbins]

OK, TMO plotting fixes:

Friend/Neutral/Foe and merchie/warship colors are killed, both on ship position plots and sonar vectors. This is information that sonar, radar, and in most cases, visual sighting would not give you. TMO totally nerfs it with black for everything.

Target silhouettes are replaced with round position markers. Same as above, information not available to real observers. In the stock game you can even identify a radar target by its shape, a definite no-no if you're seeking realism. And you know the length of your target right on the plot. All that is TMI! Round target position indicators for everybody!

Target ID, course, speed text is gone! Sight a target on the horizon, whip over to your nav map, click on the colored silhouette and see identification, course and speed? Don't try that with TMO. Nerfed. "Fast" was a giveaway a narrow speed range. No more, you have to determine speed for yourself.

x on the attack map is gone. This one I don't necessarily agree with. The back end of the vector is still the torpedo impact point, so no real harm done, but comparing TDC data to actual position was central to real targeting. No captain would shoot a torpedo without confirming the value of his solution and many shots were stopped by the officer in charge of the TDC (could change from boat to boat) announcing "bad solution. Do not shoot." He knew this because he was comparing the position output by the TDC to plotted position and finding that they didn't agree. You can't do this with map updates off. A real skipper would lose his command if he were to waste torpedoes in this manner. TMO preserves your ability to perform this indispensible function without letting you cheat.

Is that it? I think so. I'm working strictly from memory on my work computer. So, what is the weakness of the TMO plotting system? There is one.

That is perfect positioning of visual targets on your plot. It's interesting. The mission editor lets you assign a spawn point for a target and say "start this guy within 10 miles of this spot." But it doesn't say, "Ok, this is a visual target, fog, rough seas, 4500 yards, plot this anywhere within 500 yards of its real position." In other words, the game could plot with a random error within a certain uncertainty determined by the qualities of the sighting, but the devs chose not to. They had already done 9/10 of the work in their mission editor!

In the example above the 500 yard uncertainty could be different, based on visibility, range, sea state, sub crew experience, etc, so that each sighting would have its own tailored uncertainty. The position would then be plotted in a random direction and with a random error up to the uncertainty number in position. Add that to the wishlist for Silent Hunter 5!

So what do you do? Throw out the baby with the bathwater, kill the map updates, drive your sub with a paper bag over your head and claim you're playing realistically? Or use the TM plotting system and just don't take any measurements off visual positions?

I think I'd have a problem deciding if I had a boat without radar. Neither would seem right and I might end up turning map updates off, although that would also kill my air radar: an unacceptable situation. I'm not happy with either way if you don't have radar. You might be best served using TMOplot and not measuring anything from a visual position on the nav map. It's not perfect but its the best we have for now!