Periscope depth? Am I missing something?

Julhelm · 06-07-17, 03:18 AM

Not sure, I think 65 feet is probably correct, but 50 feet was in there intially because RSR had it and I guess it just stuck. And we intitally had problems with the ocean clipping the scope (because we hadn't figured out how to mask the water to keep the player from seeing under the water) so we initially had the viewport sit much higher at a comfortable distance from the waves.

Sledgehammer427 · 06-07-17, 04:48 AM

For those having trouble with broaching, usually one of the things I've tried is to approach around 55-60', then use the ballast controls to fine tune the ascent the rest of the way. After a couple practice runs I can hit 50' on the button every time

The Bandit · 06-07-17, 07:38 AM

Quote:

Originally Posted by Sledgehammer427

For those having trouble with broaching, usually one of the things I've tried is to approach around 55-60', then use the ballast controls to fine tune the ascent the rest of the way. After a couple practice runs I can hit 50' on the button every time

This and a bit of down angle on the planes will (-5 to -10) will keep your ascent in check and your sail whetted.

Wildcat · 06-07-17, 04:12 PM

Periscopes are still important.

Check out the documentary called "Submarine School", there is an example of some periscope drills they use in there, as well as photo recon. The documentary gives some insight as to when you should and should not use the scope.

Of course, unlike in that documentary, you don't want to be getting within 1500 yards of warships equipped with passive and active sonar, it's highly likely they'll detect you even if you're at 2 knots with everything turned off.

But for example, if you are tracking a merchant ship, the periscope is very useful for getting exact ranging (Stadimeter or just old fashioned math if you are hardcore and know the formula for your particular scope and zoom level) FWIW the formula for 1.5x zoom is 19.1*mast height / number of periscope ticks from waterline to top of ship's mast. Resulting range is in yards. Formula can be modified for any zoom level. Note, this works in real life but I don't know about in this game. I know some games have FOV problems or the periscope ticks are not properly spaced, etc. Only a few games I have played such as Steel Beasts and ARMA have accurate optical tick mark systems.

When facing off with a merchant the risk of detection is minimal and the accuracy of a firing solution is greatly improved.

Besides that, the periscope is used to monitor before and after dives and surfacing, and the scope can also even be used to check out the bottom of a ship's hull. In games this has not been used to very good effect yet, but sensitive information has been acquired in the past by getting under a ship and photographing its screws and rudder.

The correct PD for 688i's is 65 feet, 56 feet or so for venting. This seems to be the standard from all the dives I have seen in the public domain. I suppose it's possible you could run with the decks awash and only the sail sticking out, if you wanted to. That would likely be about 50 feet.

to the game designers, for what it's worth, if your game world is truly round and the periscope "camera" is not at the mathematically correct height, it will mean that you cannot do trigonometry to correctly determine a contact's range based on mast height. If the boat is at 65 feet and the periscope is sticking out of the water 12 inches, the camera must also be placed 12 inches above the water in the game world. I realize that I'm probably the only active person in the entire sim community who still does this, but yeah.. !

Tshark · 06-07-17, 06:09 PM

Thanks for the reply guys. So as far as Cold Waters goes many players seem to using the periscope incorrectly i.e. when aircraft and warships are around. This is probably why there are so many requests for a PD hotkey and complaints about the aerial ASW.

Wildcat · 06-07-17, 06:28 PM

I am not sure about that. If you have already been detected, and you know you've been detected (Aircraft dropping sonobouys around you), it may pay dividends to take a -brief- look around you to get a picture of what is really happening.

You generally can't hear aircraft well underwater, so knowing how many aircraft are around you may be beneficial in planning an escape route.

If you see there is a helicopter doing a ladder or barrier search to the north of you and there's nothing off to the south, you may as well not go into his search pattern. You may be able to plan a flanking route or an escape route.

Frigates sitting with their engines nearly stopped are very quiet, you'll detect him on the scope farther than you will with passive sonar - you can get him up to around 15km away whereas you might not hear a silent warship until 3000-4000 yards away. If you fire on a ship from 6000-7000 yards, you will be able to clear the firing position and his helicopters or aircraft will have a difficult time finding you with nothing but a LOB on your torpedoes - you'll be long gone. Trawlers are virtually silent when they're sitting still or with engines off. The only way to find them passively is with a scope, or ESM if he's got his radar on.

Periscope can also help if you have information overload. Too many sonar, ESM, link contacts can be very confusing. Taking a quick look on the scope can really sort you out mentally.

Finally, using the scope around warships is not necessarily a bad thing especially if you've got torpedoes in the water already. If your firing position was bad, the enemy already knows where you are, it's not going to hurt to take a look before diving and clearing the area. Just don't waste a lot of time doing it.

Berserker · 06-07-17, 08:02 PM

Practice makes perfect...From 150 ft with 10 degree up on the planes at 1/3 speed 5 knots push x at 65 ft and you level off at 49 ft...

06-07-17, 04:48 AM	#2
Sledgehammer427 PacWagon Join Date: Jun 2007 Location: Drinking coffee and staring at trees in Massachusetts Posts: 2,908 Downloads: 287 Uploads: 0	For those having trouble with broaching, usually one of the things I've tried is to approach around 55-60', then use the ballast controls to fine tune the ascent the rest of the way. After a couple practice runs I can hit 50' on the button every time __________________ Cold Waters Voice Crew - Fire Control Officer Cmdr O. Myers - C/O USS Nautilus (SS-168) 114,000 tons sunk - 4 Spec Ops completed V-boat Nutcase - Need supplies? Japanese garrison on a small island in the way? Just give us a call! D4C!

06-07-17, 08:02 PM	#7
Berserker Aggressive skipper Join Date: Nov 2012 Posts: 328 Downloads: 2166 Uploads: 0	Practice makes perfect...From 150 ft with 10 degree up on the planes at 1/3 speed 5 knots push x at 65 ft and you level off at 49 ft... __________________ Shoot,Move,Communicate..Kill,Destroy,Eradicate...

06-07-17, 03:18 AM	#1
Julhelm Seasoned Skipper Join Date: Jul 2007 Location: The Icy North Posts: 693 Downloads: 189 Uploads: 0	Not sure, I think 65 feet is probably correct, but 50 feet was in there intially because RSR had it and I guess it just stuck. And we intitally had problems with the ocean clipping the scope (because we hadn't figured out how to mask the water to keep the player from seeing under the water) so we initially had the viewport sit much higher at a comfortable distance from the waves.

06-07-17, 04:12 PM	#4
Wildcat Engineer Join Date: Jan 2002 Posts: 215 Downloads: 69 Uploads: 0	Periscopes are still important. Check out the documentary called "Submarine School", there is an example of some periscope drills they use in there, as well as photo recon. The documentary gives some insight as to when you should and should not use the scope. Of course, unlike in that documentary, you don't want to be getting within 1500 yards of warships equipped with passive and active sonar, it's highly likely they'll detect you even if you're at 2 knots with everything turned off. But for example, if you are tracking a merchant ship, the periscope is very useful for getting exact ranging (Stadimeter or just old fashioned math if you are hardcore and know the formula for your particular scope and zoom level) FWIW the formula for 1.5x zoom is 19.1*mast height / number of periscope ticks from waterline to top of ship's mast. Resulting range is in yards. Formula can be modified for any zoom level. Note, this works in real life but I don't know about in this game. I know some games have FOV problems or the periscope ticks are not properly spaced, etc. Only a few games I have played such as Steel Beasts and ARMA have accurate optical tick mark systems. When facing off with a merchant the risk of detection is minimal and the accuracy of a firing solution is greatly improved. Besides that, the periscope is used to monitor before and after dives and surfacing, and the scope can also even be used to check out the bottom of a ship's hull. In games this has not been used to very good effect yet, but sensitive information has been acquired in the past by getting under a ship and photographing its screws and rudder. The correct PD for 688i's is 65 feet, 56 feet or so for venting. This seems to be the standard from all the dives I have seen in the public domain. I suppose it's possible you could run with the decks awash and only the sail sticking out, if you wanted to. That would likely be about 50 feet. to the game designers, for what it's worth, if your game world is truly round and the periscope "camera" is not at the mathematically correct height, it will mean that you cannot do trigonometry to correctly determine a contact's range based on mast height. If the boat is at 65 feet and the periscope is sticking out of the water 12 inches, the camera must also be placed 12 inches above the water in the game world. I realize that I'm probably the only active person in the entire sim community who still does this, but yeah.. !

06-07-17, 06:09 PM	#5
Tshark Sailor man Join Date: Aug 2015 Posts: 49 Downloads: 52 Uploads: 0	Thanks for the reply guys. So as far as Cold Waters goes many players seem to using the periscope incorrectly i.e. when aircraft and warships are around. This is probably why there are so many requests for a PD hotkey and complaints about the aerial ASW.

06-07-17, 06:28 PM	#6
Wildcat Engineer Join Date: Jan 2002 Posts: 215 Downloads: 69 Uploads: 0	I am not sure about that. If you have already been detected, and you know you've been detected (Aircraft dropping sonobouys around you), it may pay dividends to take a -brief- look around you to get a picture of what is really happening. You generally can't hear aircraft well underwater, so knowing how many aircraft are around you may be beneficial in planning an escape route. If you see there is a helicopter doing a ladder or barrier search to the north of you and there's nothing off to the south, you may as well not go into his search pattern. You may be able to plan a flanking route or an escape route. Frigates sitting with their engines nearly stopped are very quiet, you'll detect him on the scope farther than you will with passive sonar - you can get him up to around 15km away whereas you might not hear a silent warship until 3000-4000 yards away. If you fire on a ship from 6000-7000 yards, you will be able to clear the firing position and his helicopters or aircraft will have a difficult time finding you with nothing but a LOB on your torpedoes - you'll be long gone. Trawlers are virtually silent when they're sitting still or with engines off. The only way to find them passively is with a scope, or ESM if he's got his radar on. Periscope can also help if you have information overload. Too many sonar, ESM, link contacts can be very confusing. Taking a quick look on the scope can really sort you out mentally. Finally, using the scope around warships is not necessarily a bad thing especially if you've got torpedoes in the water already. If your firing position was bad, the enemy already knows where you are, it's not going to hurt to take a look before diving and clearing the area. Just don't waste a lot of time doing it.