I have heard that, on submarines, the time of sunset is reported and lights are changed from white to red. I believe it is the “Officer of the Watch” who reports this to the Captain. But, why is this done? As long as each man knows when s/he is on duty, and sleeps off duty, do they really need to know day and night? Is there still some psychological reason behind this, perhaps? - Jinx
My guess is that’s exactly why. People get pretty wacky when their circadian rhythms are disturbed. The US military has all sorts of little tricks for keeping morale up, and they particularly like the cheap ones.
Does anyone else have a more solid answer?
IANAS, and they’ll probably show up soon, what with their crazy 18-hour days and whatnot.
Anyway, my understanding is that the control room goes to red at night so as not to spoil the night vision of anyone who might want to use the periscope, and to reduce the likelihood of anyone topside seeing bright, white light come out of the surfaced periscope.
I am not certain that the rest of the boat goes to red. With the odd six-on/12-off shifts they use, it may simply complicate things.
Do they really still use optical periscopes? I would think it’s all done with IR cameras and whatnot.
Hi everyone…
To be honest, I don’t know all the reasons why sunrise and sunset are recorded underway, aside from Redsland’s good point that we rig for red when using the 'scope at night (otherwise, control is lit normally), and I would imagine it’s important for other visual counterdetection considerations… the scope may be camouflaged, but if you silhouette it against a sunrise, it may not do you much good. That’s not really my bailiwick.
The rest of the boat doesn’t rig for red, although lights in the berthing areas are always dimmed. There’s way too much to be done in those 12 hours off-watch, not the least of which is trying to squeeze in a couple of hours of rack-time.
We use Zulu time (GMT) underway, but as sonarmen, knowing the local time IS an important consideration, especially for predicting the concentration of merchant traffic/trawlers/etc.
And, friedo, only now is the submarine fleet coming around to electronic, non-penetrating photonics masts. They’ve been playing with them for a while, but the USS Virginia (SSN 774) is the first submarine designed to take advantage of it. 688s and older boats had to put control in upper level, because the periscope came down through the sail and penetrated the pressure hull there. On 774, control is in middle level (which, of course, is wider than upper level) because the mast is fully enclosed in the sail and sends visual data electronically, instead of through a bunch of prisms.
You can read more here. Apparently, http://vaclass.navy.mil, which had some pretty design and development pictures, is now defunct.
Well, this is my first post… hope you guys go easy on me.
Welcome to the Board, Tyrant. Lots of good information, great first post. And at the very least, you’ll be able to tell people what it’s like to go out on a submarine for stretches of time. It’s always a good thing to be able to bring something to the table.
Redsland and TheTyrant have pretty much nailed it.
Welcome to the SDMB, Tyrant! There are several ex-bubbleheads around here, including me. I served as a JO on an improved 688-class sub about ten years ago.
BTW, Jinx, the Officer of the Deck (OOD) is the officer in charge of the boat so that the captain need not remain in the Control Room 24 hours a day. The OOD sends the Messenger of the Watch (a junior enlisted guy) to inform the captain about routine things such as time of sunset.
As TheTyrant mentioned, subs operate on Zulu time (GMT), so the actual time of sunset may have no relation to the time of day in the boat. It is important for the captain to be aware of whether it is night or day on the surface, should the sub have to go to periscope depth or surface.
I ahve absolutely nothing useful or informative to add, but I did want to comment that in one episode of Star Trek: The Next Generation, we see Commader Data relieve Commander Riker as OOD (not that they used that term on the show, IIRC). When he does he anounces the start of the night shift, and the lights suddenly dim noticeably. I thought this was a bit bizzare, not only because we’d never seen it before, but because it made no sense whatsoever from either a practical or psychological perspective. I’m gratified to know they were at least paying homage to genuine naval practice.
I might be crazy here, but aren’t there low-frequency types of communications that the military (specifically, the Navy) uses for communicating with subs? Seems to me that a system like that would work better at nighttime than the daytime. Then again, this whole idea seems like one of those “phantom memories” from reading SSN by Tom Clancy
There is a very low frequency communication system that pentrates the water and allows shore to issue commands to the subs. But because the signals have such a low frequency, it takes a long time for each character to be received. Thus, the message most often sent this way is a very short version of “come shallow and raise your antenna, we have something to tell you.”
ASAIK, this system is unaffected by time of day.
If it doesn’t seem to make sense in the Navy, there is a good chance it’s a tradition 
When I say tradition, I don’t mean to imply that we haven’t found a practical use for doing whatever it is that we strangely do, only that we have been doing it for hundreds or thousands of years and we probably started for no better reason than that we were bored underway and noticed the sun was rising and setting.
Unsurprisingly, as undersea warfare is a relatively new advent, they adopted the traditions of surface vessels.
Finding the origin’s of Naval traditions is tricky, as this stuff has been around for forever. I bet that even in the days of The Iliad and the Odyssey they had some sort of a sunrise/sunset tradition.
The nearest practical example I can find for you is here, as carried out by the British Navy circa. 1700-1750:
If you ask me, they just liked the thrill of shooting guns first thing in the morning 
After interrogating a cow-orker that spent four years underneath the Pacific Ocean I’ve decided that the answer must be that it’s partially psychological and partially practical.
Like Bald Taco said, people get upset when you disturb their natural pattern of sleep. Deliberately depriving a subject of his knowledge of day and night would certainly work (and has doubtless been employed) as torture. No reason to subject friendlies to that kind of unnecessary stress.
As far as practicality, surface ships also use red lights at night. White lights on parts of the ship visible to the enemy would make pretty good targets at night, especially to marauding aircraft.
Subs care if it’s evening cuz that’s when their doms pay most attention to them.
In the navy
Can’t you see we need a hand
In the navy
Come on, protect the motherland
In the navy
Come on and join your fellow man
In the navy
Come on people, and make a stand
In the navy, in the navy, in the navy (in the navy)
WOOT, another person in Connecticut=)
My husband just retired in September, twilight tour was on the Miami=)