Beware of underwater obstructions!!

[Captain Jeff]

While looking through the internet for tips on how to play Silent Hunter 4 I noticed some threads dealing with "sudden death" where people were using time compression while they moved through what they thought was open ocean and suddenly their sub was sinking and they did not know why. The time compression never slowed. They just suddenly found themselves sinking.

Although I'm new to the sim I ran across a situation that may explain some of these instances. I had finished my first war patrol off of the coast of Japan and was making my way back to Pearl. I had a few torpedoes left, (fuel was the issue) so I was patrolling while making my way out of Japanese waters. It was daylight so I had submerged to 150 feet and was using 64 time compression while I stopped every 20-30 minutes and went to the sonar station for a listen. I had just finished my hydrophone sweep and went back to the map to bump up the time compression to 64. No sooner had I bumped it up then the "shallow water" warning came on and I went back to normal time. In normal time, I cruised over the "shallow water" warning for about a minute before it went away. I wish I had thought to do some pinging to check the ocean floor in this area but, sadly, I did not.

This happened as I was crossing the Bonin Islands. I was at about latitude 31 50 N and was almost directly between an island to my north and an island to my south. Maybe there are some sort of land masses sticking up in between the islands in this chain. I got to thinking that if I went through there at 200 feet and was using a higher time compression then I might have hit that land mass before the sim could even click down to low compression to warn me of shallow water. Maybe this could explain the sudden death syndrome, or at least some of the instances. The "shallow water" warning really did not last that long, almost like a spire was sticking up from the ocean floor.

At any rate, beware of that underwater land mass at about 31 50 N in the Bonin Island chain. It could get you.

[TorpX]

Welcome aboard, Cap'n!



Yes, I would consider that to be good advice.

[Barkerov]

I had something similar happen to me once but with the help of the subsim community I realised that it was because my sub had taken damage and even though I thought it was fully repaired my hull was weaker than when we left port. It didn't happen right away either it took several hours real time before she cracked open and started sinking

[Rockin Robbins]

Under normal circumstances and time compression under say.....256, the game takes a virtual sounding every so many seconds. Is the water under x feet deep? Yes, return TC to 1. No? Onward through the fog!

But when you really crank it up, to 1024 or higher especially, if it was real time, the virtual game soundings might take place an hour apart instead of five minutes apart in submarine time. If the game didn't back off on the sample rate it would choke to death you know.

So if you hit shallow water and virtual soundings are an hour apart in sub time that's plenty of time to get five miles inland before the next sounding. Then the game says "speed, 20 knots, water depth -150 feet. Looks like a collision to me. CRASH, BOOM, DONE, DEAD."

It's really important that after you plot a course, you scan that course at zoomed in level to ensure that there's no land in there too small to see when you're zoomed out. If you have to rip through there at 2048x it can save your life.

[De Ruyter]

Originally Posted by Captain Jeff

It was daylight so I had submerged to 150 feet

Do you follow this practice to be historically accurate, or is it a good practice in the game? I am used to SH1, so there was not that much need for it. It seems like it would be a waste of battery and compressed air in case something sudden did come up where I would need to stay underwater. Then again, if I had to stay underwater I guess I would be running silent, but I don't like to attack on the surface unless the ships are unarmed. Speaking of which, do all ships carry guns, or are there unarmed merchants like in SH1?

[Captain Jeff]

I started running submerged during the day to be historically accurate but soon found I like the technique. That's my personal taste. There are others who like to stay on the surface until a contact. You can get good results either way.

I only went to 150 because one of the mods I use increased an airplane's ability to detect me while underwater. I kept having to go deeper and deeper just to avoid getting killed by the planes. I've since got another mod that corrects that problem. I'm slowly creeping back toward the surface, wondering if I can patrol at 100 feet without being easily spotted by an airplane.

I stay under from dawn to dusk. I listen at my sonar station to find targets. There's several techniques you can use to determine a targets course and speed just from using passive sonar. I figure out where they're heading and try to get in a good position for a shot. I'll run on the surface during the day if I need the speed to get in position but, other than that, I stay under.

I come to periscope depth every 20 to 30 minutes of game time. I'll have a look around even if I don't have any sonar contacts. I look for airplanes or sampans. If I spot them I'll dive deeper. After a day of doing this, my battery is at about 50% and my compressed air is at about 66%. There's still plenty left if I need to go under again. And I'm not nervous about increasing my speed to meet a contact. There's plenty of battery. (I patrol at 1/3 engine speed. To speed up, I'll go to 2/3 and, occasionally, full.) I don't worry about needing a full battery to evade if I spot something. Silence is the key to my evasions so when a destroyer is hunting me I'm never moving faster than a couple of knots.

And if you find a spot where you like to hunt and think you might be back on future missions, then ping that spot whenever you can get away with it. Learn that ocean floor!!! I used to SH1 as well. I've got to say, the charts used on SH1 are superior to the charts on SH4. Almost no information on SH4 except where the 50 foot shallow water starts.

[Majestik 909]

I want a patch that will allow you to de-clutch the diesel and allow the opposite screw to rotate in the current and charge the battery while submerged on one electric motor....

[Majestik 909]

When I had command of the old U-194, i would run surfaced at night and chase radar co, ntacts. By day I would run submerged and, in general, take position in the shipping lanes and wait for targets. I would often attack on the surface with torpedoes and deck gun simultaneously if encountering un-escorted vessels.

When I was promoted, at 250,000 GRT, I was given command of a new Typ XXI in late 1944 U-796, I no longer had a deck gun, but I also had acoustic torpedoes. I would then sink the destroyer escorts before attacking the convoy.

On one mission, f.d.u. 33 directed me to intercept a liner that had been converted to a transport, between Fremantle and Port Elizabeth. That Titanic-esque liner was protected by 9 destroyer escorts. I literally spent around 6 hours in real time to complete that mission. It was difficult to pick off the destroyers, but i found that by using the liner as a shield i could fire around it.

Also beware of old shipwrecks. I have come close to hitting at least one in around 150 feet of water and ot wasn't on the map. I only saw it because I switched to underwater view by accident while playing the Gramaphone for my crew....

[Armistead]

they're numerous reefs, islands, etc., where the water doesn't shallow out and and tc doesn't drop...but you'll soon find your sub totally grounded and game over

[De Ruyter]

Originally Posted by Majestik 909

Also beware of old shipwrecks. I have come close to hitting at least one in around 150 feet of water and ot wasn't on the map. I only saw it because I switched to underwater view by accident while playing the Gramaphone for my crew....

I wonder if the game tracks where you sunk ships and maintains the wrecks on the ocean floor, especially in shallower water. Out in the open Pacific, where the depths far exceed crush depth, I guess it would be a moot point, they would not affect you anyway.