I'm struggling to understand the Snort principle, it there a diagram of the system anywhere?
Try this - it's a Flash diagram
The water is pushed from the cylinder by sucking air from the Snort tube in the conning tower and blowing it into the ballast tank. unlimited yet realistic dives can be achieved.
A simple servo operates the vent valve on the top of the cylinder.
In the event of an emergency only, the on-board gas tank is discharged into the ballast tank when the fail-safe kicks in. This will recover you from almost any deep pond or lake as the pressures in the gas system are much greater than any air pump.
If you were in a pool where you can easily recover the boat, (e.g. swimming or paddling pool) there would be no point in using the gas, so you would only use the Snort.
Boat is trimmed with the tank full of water, so the Snort tube is just above the surface. So, if boat is at 'stop engines' flooded ballast tank (or just dead in the water), it will float to just below the surface. A fail-safe, if you like.
Most people operate their boats in lakes so that they can see them. (Very wise) and so a snorkel cutting through the water is almost welcome if the light is wrong.
To dive, flood the ballast tank. To deep dive, dive planes down, full ahead and down you go! I found on my D&E Skipjack, that I didn't need to adjust forward dive planes, so these can even be fixed.
To surface, dive planes up, slow down, and up she pops to expose the Snort tube, suck air and blow the ballast tank!
It works really well for me, and I'm relatively new at R/C control of these boats.