I've been wanting to do that also. The subs could actually "talk" deeper than PD later in the war, so I was wondering about raising the level of the 'antenna' maybe, but haven't gotten around to experimenting with it yet. I haven't looked to make certain, but I think it is tied to "radar depth", aka: "Snorkel depth", or, if modded further - aka: "Decks Awash"...
