I made the max fire range 35000 meters or 18. 9 nautical miles, to "encourage" the warships , mainly BB, CA, to open fire at longer ranges in surface battles, instead of always waiting until at what is point blank range... especially in daylight. The default is just 10000 meters. Result thus far has been that in daylight, depending on factors such as fog, type of vessel (BB will engage further out than say a CA) they(capital ships, mainly BB with their main batteries) are engaging at around 13000-18000 yards, sometimes more, depending on conditions.

At night obviously not firing at those ranges as can not see one another that far out so result being get historically accurate (mostly) battles such as Savo Island where they fight at what is point blank range for warships. Then, in 1944 such as at Leyte Gulf (Surigao Strait) US battleships (last battleship v battleship action in history) will open fire at longer ranges now, last testing they opened fire on japanese at 9,000 yards, sometimes little more or little less at night, depending on conditions. Previously, would wait until 5000 yards or so. This is due to improved radars assisting the visual sensors.


Of course this has no effect on their spotting player submarine as too low profile to be spotted or detected on radar at that distance. Again, am in the PTO and IJN radar was not up to par with allied, so that is reflected in the sim with my radar mod. I can pull off night surface attacks on convoys with radar equipped escorts. Now, it certainly makes it riskier and tougher to pull off, esp after torpedoes hit, they are alerted, it helps them locate quicker and maintain contact beyond visual range, also helps with gunnery accuracy but still possible.

At some point I want to worked on some of the ATO mods for SH 4 and maybe even SH 3, to make it where U boats can perform realistic night surface attacks, esp in the early war. Main thing is the nights being dark enough to interact with proper settings for sensors and sim.cfg


Far as the fog factor goes, like I said it's not that is really doubles their visual range, as there are a host of other factors but lowering it to 0.5 does remove some of a handicap caused by fog on visual sensors. I did this because at 1.0 the handicap is pretty strong and when checking weather, there seems to be a light fog present majority of time and noticed it hinders the escorts, allowing player to get away with a bit too much in daylight and esp at night, at times even rendering escorts too ineffective on surface at night, when combined with a dark moonless night, and a fog.

Now, I have two CFG's, one for early to mid war (1941-late 1943) and another for late 1943-end of war. They are mostly the same except for in visual, the enemy speed factor is increased from 14 to 17. and fog factor is at 0.8 instead of 0.5 .


This was done as war changed in pacific and player has to use different tactics, night surface attack became common place while japanese started in late 1943 running more convoys, with multiple escorts vs before most convoys had one, sometimes two escorts and many ships sailed without escort until mid 1943. In late 1943 and especially in mid to late 1944, they adopted some Alliedesque tactics, running large (by their standards) convoys of 12-20 ships with 4-6 escorts, sometimes more. These are convoys, that like actual us submarines did, player can get inside, attack from within on surface and in many cases get outwithout having to dive, emulating what actual US submarines did often. Now, problem is the the early-mid war settings for speed at 14 knots became a problem in late war as at times player at times in order to get inside convoy needs to use high surface speed and even when at reasonable distance during testing, I was getting spotted for going on 14 knots or slightly over due to inherent nature of having to operate closer to enemy escorts and merchants, at times preventing from pulling off historically accurate attacks such as from within, so I raised the speed factor in visual section of .cfg a bit since player in mid to late war will likely be operating on surface Now can still be detected below 17 knots, just provides a little more flexibility. if player needs to speed up momentarily to .

Early war, since not operating inside convoys on surface and escorts are typically ahead of astern, need handicap slightly lower so they can respond esp after attack.

I spent , many many hours during development of mod tweaking this, to balance things properly and found it with the settings I have. Main goal was so player could operate in a historically accurate realistic manner , but maintain the toughness TMO is known for. I am overall happy with results as achieved this, but as has said, there is no one solution because so many factors come into play. May find in one attack the fog hindered the enemy and in next one may find it really did not or it may have helped in a subtle manner during escape.

I think, you have to write this in header of the thread of your mod, it's very important and interesting information, making it much more inviting.

Good idea. I included a pretty detailed write up in the download with a lot of same info but will do so. The surface engagements is something I developed after last release, will be included in next release.

Thanks and glad you found that post. I have read it and consult it often as a reference, if need some refreshing. What Ducimus said is accurate but of course, a lot has been learned about the sim and sensors, since he created that post. Plus a lot of things have been modded as well. Great basic information though.


Something that does not discuss is how your location on earth (in SH 4) has can affect your experience. I was not sure about this, but when explained by a veteran modder or two and base don my experience in extensive testing, would say yes. I was surprised this was modeled in the sim but have learned that SH 4 is a bit more complex than initially seems.

I have noticed that closer to the equator and just south of equator, player is less likely to encounter a thermal layer and enemy sensors even in earlier part of war tend to be more effective.

As a final test of my mod, I played with a Gato from new construction in early 1942 until end of war, patrolling all different parts of the pacific, transferring around to get a feel for things. First time have ever survived the war in anything "les" than a Balao class in TMO, usually in TMO a Gato and lower just don't have the deep diving ability and strength to stand up in later war. Of course, with my changes I made thing a bit more realistic, while preserving difficulty and challenge, so I survived, but in 1943 when operating out of Brisbane, so patrolling near or just north and south of equater, I was getting beat up every patrol, nearly lost boat twice. Enemy just seemed to be tough, even though still did not have the top notch sensors of late war escorts. Interesting enough, it paralleled history in sorts as I had the USS Drum SS-228, which was out of Brisbane in 1943, was heavily damaged in November 1943, conning tower was cracked during depth charging, leaking and began to buckle on next test dive had to go to Mare Island, CA after to have it replaced. I kept pretty extensive notes and wrote up patrol reports posted in the reports thread and on my pc for reference as well, so could see a pattern when read them, which supports this.

Anyway, in 1944/1945 I was out of Pearl Harbor noticed when patrolling further north such as Sea of Okhotsk or North Cost Honshu, enemy sensors, even best were overall not as effective and more thermal layers were encountered. This spurred some discussion and extensive testing and even more after it was explained to me, seems to fit.

I don't have enough experience in the Atlantic side of things to comment on how this plays out there, as may be modeled differently etc . Long and Lat do effect visual sensors as well have been told and noticed, fog comes in to play as does the light. Ah, the complexities of SH 4 lol.

Interesting. That is true, I believe I did find one at 90 ft on a recent patrol though. However, that is too shallow to hide under lol as they were still ble to track me with ease and put charges super close until I went to 375 ft, but most layers are found somewhere between 150-300 ft.

Yes, I do recall in OM that it became hell to run a patrol in 1943 onwards, mainly due to aircraft. I had to heavily modify the airstrike.cfg and others to stop the absurd number of planes inherent in SH 4, but their skill an ability to detect, hunt made it difficult to survive even with reduced number. I believe once or twice I made it to fall 1944 but always ended up getting killed, by AC or hedgehogs/DC from nasty escorts. I did not mind because it reflected reality of Allied ASW by that point. TMO planes are inherently dangerous, esp early war without radar and in late war, they have a sensor simulating MAD, can detect and depth charge player submarine at 300+ feet, one nailed me at 375, caused serious damage.

yes, i have done the same. otherwise playing is just too tough and no fun at all.


hedgehogs....do not speak to me of hedgehogs. they are the devil's spawn!

lol yes they are evil. I recall a great career in OM, made it from 1939 to October 1944...attacked a convoy. Two US DE stayed behind hunting. Boat was a wreck from DC but no hits from hedgehog. 17 hours under water, surfaced at night, as got underway....aircraft spotted, forced a dive. Well here comes the DE's again joined by two more. Evaded them about 45 minutes but could not shake them. Finally a JCB Class DE came in with hedgehogs and got a hit, hull damage, flooding, then a second one came in, boom, another hedgehog hit, hull collapsed game over. Honestly, prob should have been over after first hedgehog hit. Know of any boats that survived a hedgehog hit?

Japanese never deployed ahead throwing ASW mortars (hedgehog) but were developing them, so on a very limited basis in TMO they now appear in 1945...provide a nasty surprise.

How about in real life, during the war? Are any known to have survived a hedehog hit?

No prob. Well, was wondering if any took a hedgehog hit and made it back to port to tell about it. Possible some survived initial hit and were lost after, en route home etc. The explosive charge on the hedgehogs were not the large, but enough to hole a submarine from what I understand.

If memory is serving Me right... :hmmm: & I think it is... hedgehog explosives, the detonator, was not in what depth it was before going off, the verdampt things were made with a contact fuse. Meaning that with their ability to be fired off well ahead of the charging in destroyer or escort ship so enabled with the devil's spawn things... the charges would sink down at a fast clip...Any making contact with the hull, well... it's be a bad day for the crew.

The explosion from it, would be right there, on the subs hull... very much guaranteeing hull damage & the sub getting holed.
Of course, the verdampt things, did not need to be big, owing to the... knowledge of explosives being advanced, at the time they were intro'ed into the war, that what was used for depth charges, would not work for those devil's spawn things...

"big things come on small packages" expression, comes to mind here. :yep:

:Kaleun_Salute:

M. M.

If there are multiplication then if the fog factor = 0.5 the more fog make AI vision better and the fog factor = 1 make no handicap.