Pedro, I think you may be able tell if this is a no s**tter or maybe I was hallucinating. Does anyone else know about this snorkling procedure...

In 1962 (or so) the Sirago made a trip north and stopped in Halifax, Nova Scotia. We tied up at a pier with a British submarine outboard of us. We stayed for about a week??? I visited the boat one afternoon and was given the grand tour. I found out that the boat had a detachable snorkle mast that folded down onto the deck when not in use. To use it, the boat would have to surface, rig the mast up then dive to snorkle. To be honest I never saw the exhaust mast. The boat was old but I was told they regularly dove to 700 ft? I had doubts about that, but?

Anyone?