Buoyancy wheel driven by HHO electrolysis.

[kolbacict]

Compare a football released under water. Only when it breaches the surface, does it gain speed.

Are you sure?  By what forces it accelerate ?
The Archimedean force is no longer there, but the force of gravity has appeared, directly opposite.

[Cloxxki]

Are you sure?  By what forces ?
The Archimedean force is no longer there, but the force of gravity has appeared, directly opposite.

Drag, simple drag.
That feeling when you stick your hand out the window of a car on the motorway. Feel that force oushing the hand back?
Guess how much slower you only need to move your hand when a meter under water for the same force? All that force you feel on your hand out the car window, is actually slowing the car down or significantly added to the power demand to keep that speed.
Fill a basketball or yoga ball with water and compare how hard it is to make it reach 1 m/s horizontally compared to when it's tethered from a high beam when it's actually also being raised.
If you want your buyoant vessel to drive a generator, you better have a really good idea of how that's going to work without losing >50% right there to moving water around before the generator's 10-20% losses (at optimal input rpm) are introduced. And that is assuming you manage to drive any generator at optimal rpm without additional gearing.

[Willy]

You need beter bait than that to troll here Cloxxki.

[Cloxxki]

Do some reading. Written to be understandable to Redditers.

https://www.reddit.com/r/askscience/comments/5ebvi9/what_would_happen_if_you_took_a_basketball_10000/