Side view of the un-reliable Version 2.

The other view shows the steering mechanism.

Ready for a ride.

A R/C unit is added.

On the way.

Surface.

Dive! Dive! Dive!

The overall view.

The conning tower

The Stern

7_B constructed three chambers and two vents inside her hull.
Those constructions made her auto dive and surface.
She really work.

A correct amount of water needed to fill those chambers before operation.
I only fill the correct amount by chance.

So an auto dive and surface device is taken place to ensure operation.

The instruction

Adjustable diving and resurfacing

Made in Hong Kong