Yes, you could launch a canister from a torpedo tube, but I'm betting the waste disposal is a lot quieter. And a lot less likely to be heard as a declaration of war.

but nice try

Silly me. I thought UAV meant Unmanned aerial vehicle.

IIRC the US Navy does have those Cruise Missile planes in their torpedo launcher tubes for quite a few years now. Replacing that nuclear or chemical explosive payload by a decent camera would probably not be too difficult a job, right ?

Considering their long range (probably 1000km or so) and big payload (probably more than 100kg), THAT would actually be a powerful recce or ELINT/COMINT platform. Also, their terrain contour matching navigation system is also pretty nifty.

Taking all those facts into account makes me feel that the US Navy (and maybe the Tommies also) already have such gear, they are just not announcing it. The system discussed in this article is probably only more economical - a cruise missile is said to be 1 million US$ per piece. A recovery system (parachute and CO2 floating device) could make the cruise missile viable, though.

You mean rat's brains?

How does the data get from the UAV back to the submarine without the submarine raising it's antenae?

The submarine raises it's antennae for a few minutes, when convenient, for a quick handshake and download.