Max depth at which you would have been able to raise periscope

[fireship4]

I remember someone saying he used the tactic of looking for escorts passing overhead by using the periscope and asking if it was realistic. I can't remember what he said...

Also, do periscopes have a maximum depth at which they could be used without damage/flooding?

[Sailor Steve]

I don't recall reading any books in which a commander stated that he used that tactic. I think it's less a matter of how deep the periscope can safely be raised than how far you can actually see underwater in most conditions.

Game water is very clear compared to the real thing. There are many photographs showing otherwise, but usually from specific areas where the water is exceptionally clear.

[Peto]

I can't prove this but: If you can see it from a submerged periscope, you should most certainly already be hearing it. Submarines relied on sound--not as much as they do today--but sound was still their eyes when submerged. Not many skippers would be happy with his scope ten feet under the surface to notice the massive hull of a ship coming into focus. By the time you saw it, it would likely be too late to react. A ship doesn't have to hit you to ruin your day. The prop wash of a freighter going over you can suck you to the surface, even if you're at 90 feet.

I think that if the scope was up, it was out of the water.

And keep thumping that bass Sailor Steve!!!!

[TheSatyr]

Periscopes are rather delicate instruments. Even if you could raise it at depth you run a serious risk of having it damaged by the sea pressure or from the shockwave of a DC.

I'd hate to be a Skipper trying to explain to Christie or Lockwood on why I had to cut short my patrol to have my periscope replaced.

[Chock]

About the only time submariners actually would raise the scope whilst submerged, as far as I'm aware, is with the ones that could tilt upwards for sky observation. Underwater they would be able to see if there was a ship above you because of the light being blocked out more. This would be handy for two reasons, one if a destroyer had stopped to pick up survivors, you might not hear it and think it is gone, two, if you wanted to hide under a ship, it would allow you to correct the position.

Chock

[pythos]

Even when lowered, the scope is still exposed to the outside water, along with the pressure. The sheers did provide some protection from DC shock Waves. This is true for all WWII and before subs, I think even modern subs leave the scopes exposed to the pressure.

[Captain Vlad]

I like using it to see how much deeper I can get when I got myself into some horrible situation in water two shallow for any sane person to be diving in. I also use it to avoid collisions with merchant ships when prowling through a convoy.

[scrag]

It is always exposed to Sea Pressure. So it does not matter what depth in relation to the scope itself. The issue is the capabilities of the Hydraulic plant (and pressure) or the electric motors in raising the scope. BTW it is pretty much black after about 400 feet or so. Modern systems have diffculty with deeper than typical depths (say about 200 feet or so). One factor that is never modeled accurately is the Vibration of the scope at speeds greater than say 7 knots when the scope is raised deeper the PD. There is no fairing and so it is just the scope dealing with the water flow.

[Wasserbombkopf]

During the cold war, IIRC, a US sub used it's periscope to take (underwater) pictures of the underside of a Soviet ship. Pretty sure that's in "Blind Man's Bluff".