Techniques for Spying in Shallow Enemy Harbours

NeonsStyle · 03-12-20, 10:25 AM

I was given this mission tonight in Trigger Maru, to sneak into Osaka
Harbour. This is bloody difficult, since submerged, it's a 24 hour
trip from the harbour entrance, and water depth ranges from
56 to 185 feet. I went in under nightfall on the surface on a very
dark night but was still spotted by shore batteries. Next day,
I was sunk by a Sub Chaser in 56 feet of water.

So I'm curious what methods some of you use to do this sort of mission
in Trigger Maru?

propbeanie · 03-12-20, 10:06 PM

I don't do them... The game does not penalize you for not doing missions. You only miss out on the renown award for completing a mission. The only issue you will encounter by not doing the mission, is that you will not be allowed to do a Status Update and get a new primary objective assignment, so make your own. They want you to raid Osaka? Then patrol off of Kii Suido and sink everything that comes by, moving some miles away immediately after each sinking, so that you don't attract too much attention to any one spot. Lather rinse repeat ad infinitum ad nauseum. When you are out of torpedoes, head home, and hope that you don't get another similar assignment. You will get renown for every ship sunk, and they generally bring in more renown that a mission objective, which might get you 300 points tops.

Another thing you could do, is figure out where you were when you were spotted previously. Draw yourself some circles of that radius, which is generally like 9200-9500 yards. (You get three guesses why those figures stick in my mind, and the first two don't count.) Drag those circles around to the points coming in toward Osaka, and the Island in there etc., and when you are getting close to the limit, submerge until you are on the other side of the circle area. Surface, catch some fresh air, and re-charge the batteries. Another thing to keep in mind, is that the CO2 meter is whacked, and comes on too soon. You do have enough air in the boat to stay down for the daylight hours. Just don't go over Ahead 1/3. It's actually quieter if you use the knot gauge and don't go much over 1 knot, which should keep you below 50 rpm, and relatively quiet also. Stay away from patrols... easier said than done, of course... Expect it to take you a day in, and a day out at a minimum, and most likely more. Just to let you know, no US sub took pictures like that. Most of the picture taking they did was of beaches, like around Palau, and that would take them a week or more to do usually...

NeonsStyle · 03-13-20, 12:43 AM

Quote:

Originally Posted by propbeanie

I don't do them... The game does not penalize you for not doing missions. You only miss out on the renown award for completing a mission. The only issue you will encounter by not doing the mission, is that you will not be allowed to do a Status Update and get a new primary objective assignment, so make your own. They want you to raid Osaka? Then patrol off of Kii Suido and sink everything that comes by, moving some miles away immediately after each sinking, so that you don't attract too much attention to any one spot. Lather rinse repeat ad infinitum ad nauseum. When you are out of torpedoes, head home, and hope that you don't get another similar assignment. You will get renown for every ship sunk, and they generally bring in more renown that a mission objective, which might get you 300 points tops.

Another thing you could do, is figure out where you were when you were spotted previously. Draw yourself some circles of that radius, which is generally like 9200-9500 yards. (You get three guesses why those figures stick in my mind, and the first two don't count.) Drag those circles around to the points coming in toward Osaka, and the Island in there etc., and when you are getting close to the limit, submerge until you are on the other side of the circle area. Surface, catch some fresh air, and re-charge the batteries. Another thing to keep in mind, is that the CO2 meter is whacked, and comes on too soon. You do have enough air in the boat to stay down for the daylight hours. Just don't go over Ahead 1/3. It's actually quieter if you use the knot gauge and don't go much over 1 knot, which should keep you below 50 rpm, and relatively quiet also. Stay away from patrols... easier said than done, of course... Expect it to take you a day in, and a day out at a minimum, and most likely more. Just to let you know, no US sub took pictures like that. Most of the picture taking they did was of beaches, like around Palau, and that would take them a week or more to do usually...

Thanks. I've been working my way through the Silent Service series, n it seems pretty clear that if anyone was given a mission like this for real it'd
pretty much be a one way trip. I'll try your method, and if it doesn't work, scrap the mission. On default game, no mods, I snuck into Tokyo harbour once and sank a mess of ships, but Trigger Maru makes things much more interesting.

Thanks again

Cheers.

Neon

Sniper297 · 04-03-20, 06:37 PM

One thing missed a lot - how deep is deep enough? Periscope depth is good for anything except airplanes, with the scope sticking up an elite destroyer crew will see it at 500-1000 yards, if you're at 40 feet with the periscope shears above the water anyone at a range of 2 miles is unlikely to see you even in the daytime. Decks awash;

https://www.subsim.com/radioroom/sho...d.php?t=211613

You can often get within 2000 yards before being spotted, 1000 yards at night.

In general though, trick to penetrating harbors is surface at least 5 miles from any shore to recharge batteries, preferably at night, and when submerged use a SHALLOW periscope depth, 50 to 55 feet, to avoid running aground.

I often go into Osaka even when I don't have the mission, because of Kobe - lots of juicy targets, battleships and carriers, sitting at anchor in shallow water. Hard to miss when they're sitting ducks.

Plot a course at least 5 miles from land, using the compass tool to draw 5 mile circles at capes (potential shore battery locations) then avoid them or transit submerged. The dark area inside the harbor is deeper water, but the best method is to keep plenty of torpedoes in reserve for shooting your way out if needed, and move out of the way of transiting convoys and patrol boats.

Really not that difficult to get in and out of Osaka, for a real challenge try going all the way to the Tokyo docks - southwest corner of Tokyo Bay has a few spots where you can sit on the surface at night to recharge batteries. Requires a lot of patience because (1) it's a lot bigger than Osaka with fewer patrols, and (2) there are very few safe places so you have to spend a lot of time submerged and waiting for opportunities to sneak past the constant ASW patrols.

03-12-20, 10:25 AM	#1
NeonsStyle Chief Join Date: Jun 2008 Location: South Australia Posts: 318 Downloads: 187 Uploads: 0	Advice needed for Spying in Shallow Enemy Harbours I was given this mission tonight in Trigger Maru, to sneak into Osaka Harbour. This is bloody difficult, since submerged, it's a 24 hour trip from the harbour entrance, and water depth ranges from 56 to 185 feet. I went in under nightfall on the surface on a very dark night but was still spotted by shore batteries. Next day, I was sunk by a Sub Chaser in 56 feet of water. So I'm curious what methods some of you use to do this sort of mission in Trigger Maru? __________________ NeonsStyle - YouTube Channel: https://www.youtube.com/c/NeonsStyle...e_polymer=true Hit me up in the Comments or Discussion on my channel or message me on: Last edited by NeonsStyle; 03-12-20 at 09:24 PM.

03-12-20, 10:06 PM	#2
propbeanie CTD - it's not just a job Join Date: May 2016 Location: One hour from Music City USA! Posts: 9,734 Downloads: 439 Uploads: 2	I don't do them... The game does not penalize you for not doing missions. You only miss out on the renown award for completing a mission. The only issue you will encounter by not doing the mission, is that you will not be allowed to do a Status Update and get a new primary objective assignment, so make your own. They want you to raid Osaka? Then patrol off of Kii Suido and sink everything that comes by, moving some miles away immediately after each sinking, so that you don't attract too much attention to any one spot. Lather rinse repeat ad infinitum ad nauseum. When you are out of torpedoes, head home, and hope that you don't get another similar assignment. You will get renown for every ship sunk, and they generally bring in more renown that a mission objective, which might get you 300 points tops. Another thing you could do, is figure out where you were when you were spotted previously. Draw yourself some circles of that radius, which is generally like 9200-9500 yards. (You get three guesses why those figures stick in my mind, and the first two don't count.) Drag those circles around to the points coming in toward Osaka, and the Island in there etc., and when you are getting close to the limit, submerge until you are on the other side of the circle area. Surface, catch some fresh air, and re-charge the batteries. Another thing to keep in mind, is that the CO2 meter is whacked, and comes on too soon. You do have enough air in the boat to stay down for the daylight hours. Just don't go over Ahead 1/3. It's actually quieter if you use the knot gauge and don't go much over 1 knot, which should keep you below 50 rpm, and relatively quiet also. Stay away from patrols... easier said than done, of course... Expect it to take you a day in, and a day out at a minimum, and most likely more. Just to let you know, no US sub took pictures like that. Most of the picture taking they did was of beaches, like around Palau, and that would take them a week or more to do usually... __________________ "...and bollocks to the naysayer/s" - Jimbuna

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04-03-20, 06:37 PM	#4
Sniper297 The Old Man Join Date: Dec 2005 Location: Philadelphia Shipyard Brig Posts: 1,386 Downloads: 160 Uploads: 19	One thing missed a lot - how deep is deep enough? Periscope depth is good for anything except airplanes, with the scope sticking up an elite destroyer crew will see it at 500-1000 yards, if you're at 40 feet with the periscope shears above the water anyone at a range of 2 miles is unlikely to see you even in the daytime. Decks awash; https://www.subsim.com/radioroom/sho...d.php?t=211613 You can often get within 2000 yards before being spotted, 1000 yards at night. In general though, trick to penetrating harbors is surface at least 5 miles from any shore to recharge batteries, preferably at night, and when submerged use a SHALLOW periscope depth, 50 to 55 feet, to avoid running aground. I often go into Osaka even when I don't have the mission, because of Kobe - lots of juicy targets, battleships and carriers, sitting at anchor in shallow water. Hard to miss when they're sitting ducks. Plot a course at least 5 miles from land, using the compass tool to draw 5 mile circles at capes (potential shore battery locations) then avoid them or transit submerged. The dark area inside the harbor is deeper water, but the best method is to keep plenty of torpedoes in reserve for shooting your way out if needed, and move out of the way of transiting convoys and patrol boats. Really not that difficult to get in and out of Osaka, for a real challenge try going all the way to the Tokyo docks - southwest corner of Tokyo Bay has a few spots where you can sit on the surface at night to recharge batteries. Requires a lot of patience because (1) it's a lot bigger than Osaka with fewer patrols, and (2) there are very few safe places so you have to spend a lot of time submerged and waiting for opportunities to sneak past the constant ASW patrols.