A short history of diving

[SilentOption]

I think you are talking about Seabob. It does about 7 knots on the surface and 6 knots underwater according to the marketing info.
Its a bit impractical for diving. 3 knots is the threshold where your face mask begins to lift off your face unless you have one hand on it. With swim goggles however you could really rip through the water.
The last time I checked the price for Seabob was about 8-11K depending on the model.
The more common dive scooters are about half that. I have been driving wet submersibles since 1976, both in the Navy and now in my post military life. The biggest wetsub available today is over 30 feet long and runs on the surface like a boat then fills up with water and becomes a sub.
Its always a spectacle when the boat is sinking or re-emerging to become a boat again.

[off-the-grid]

Yeah, I didn't think of that.

Guess you could make a small custom windshield for it to duck behind.

Or just save 8k and get an X-scooter.