I finally got a chance to put TK-20 through her first trials today. After overcoming some intial gremlins caused by the battery shifting a little during the car journey, every thing went pretty smoothly. She was no speed demon, but still fast enough. Turning was a revalation, with independent throttles mixed to the rudder I could trun her inside 2 boat length on the surface and withing her own length under water at slow speed. I didn't get a chance to fine tune the pitch contoller, but she still held a reasonable course. Near zero water visibility and with just 3 feet of water to play with, submerged runs were kept to PD.
Click picture for video of surfaced run
Video of submerged run