It looks to me to be just like SHIII, but in feet. 165 is the shallow depth guage, 600 is the full depth guage. 165 feet is not quite 51 meters.

I think your right steve

two gages
 

The shallow water depth gage is used for when the boat is operating above 150 feet. The deep water gage is used when operating below 150 feet. Both gages are in feet and not meters. Shallow gage is for more accurate depth control. All depth measurements are made from the keel, so when you go to periscope depth (58 to 62 feet) that depth is from the keel, so the top of the shears are only about 10ish feet beneath the surface. While sitting on the surface, the depth gage should read around 18 feet.

Depth below the keel is not a gage, but a sounding indication from the fathometer.

Good explaination! One extra comment - I remember reading somewhere - and have attempted to find out where - that the US subs were the only boats that registered the depth that they were at, as from the surface to the keel.

Happy hunting :ping:

I think depth to keel is a universal standard?
 

"One extra comment - I remember reading somewhere - and have attempted to find out where - that the US subs were the only boats that registered the depth that they were at, as from the surface to the keel.

Happy hunting :ping:"

A U-boat at 12 meters is at periscope depth, which is almost 40 feet. That means depth to keel. A Fleet boat is much larger (about twice in dimension and 3 times in displacement), so her depth to keel at periscope depth is about 60 feet. In both cases the top of the shears would only be submerged about 2 to 3 meters, almost close enough to disturb a still surface.

Not to belabor the issue but I found a British web site that covers their submarine service. I received an answer to a question I sent them, about depth.

The answer came from a Chief Stoker who entered the British Submarine service in 1952 where they were still using WWII standards. Their periscope depth was 32 ft. and the depth was measured from the surface to the middle of the hull. Later they went to Nato standards - that was like most Western Navies, and now measure from keel depth.

Happy Hunting :ping: