I was experimenting with underwater propulsion and ultimately came up with this craft. It uses rotator driven propellers and so it is fully autonomous and capable of going to the deepest deeps of the SP world. It also has a magnet to pick up stuff from the sea floor (if there is any, lol), up to around 4,000 lbs.

Controls:
Throttle - set this to 100% and leave alone
VTOL - submerge/surface
Trim - speed, direction (forward/backward)
Yaw, Pitch, Roll - as usual
Landing Gear - extend magnet manipulator

AGs:
1 - lights
2 - magnet
3 - gyroscope (you may want to turn it on occasionally, especially when ascending or descending)
7 - engage magnet manipulator controls (with Pitch and Roll)
8 - disengage craft Pitch and Roll controls (useful when 7 is on)

Please keep in mind: pitch and roll are dependent on the same thrusters as speed and direction. So, no Trim = no Pitch & Roll controls. Negative Trim = inverted Pitch & Roll.

At first, the craft may be reluctant to submerge. If it is, move Trim up and lower the nose. It should go faster and smoother.

UNDERWATER CAMERA MOD BY WNP78 & GESTOUR