The tower for the air buoyancy machine goes 1000 ft above the ground. There is no water involved.
Gravity Machine # 2 is submersed in 10 ft of water.

Please look at my video again. When a sealed cylinder is moved downward in water, an equal volume of water MUST BE LIFTED.

Why is this so hard to understand? You can see it clearly in my video.

The tower for the air buoyancy machine goes 1000 ft above the ground. There is no water involved.
Gravity Machine # 2 is submersed in 10 ft of water.

The materials don't matter. The principle is the same. And it won't work.

What is wrong with the detailed analysis of buoyancy devices on Simanek's site?
What is wrong with my demonstration in the video?

No. Just as in my demonstration, I am saying that a "falling" cylinder must displace an equal volume of water--upward. There's no way around this. Look carefully at my video. Perhaps there will be an "Eureka! moment.

Buoyancy is a result of water, heavier than an object, falling under and thus lifting the object. The energy comes from the falling of the water. Thus, it is potential energy of a mass lifted in a gravitational field. There's nothing special, or even different, about buoyancy that could make it work in a gravity engine. You are still just lifting water and letting it fall back.

Obviously.
Try this:
Fill a basin with water. To the very top. Or draw a line at the top level of the water.
Now insert a hollow ball or pillbox like I did.
Push it right down into the water.

Did any overflow? Or did it go above your line?

So, you raised some water up by pushing the pillbottle down. This water WENT UP HIGHER than the original surface of the water.

It weighs what water weighs.

The difference between the weight of this water, DISPLACED UPWARD, and the weight of the pillbottle, is what we call "buoyancy." It is an effect of gravity. It is caused by the weight of the water displaced being heavier than the object displacing it.

Put some weights in the bottle so it is now heavier than water. Do the test again. Does the water rise up above your line? Yes, it still does. So by dropping the weighted bottle in the water, you are again RAISING an equal volume of water right up to the top of your basin, above the original level of the water before you dropped the bottle in.

Push the tank just under the water. It raises the water level above the line, because you have displaced the water upward.
Now push the tank one tank-dimension further under the water. Does the water rise any more above the line? No. But does water rise? Yes. The volume of water equal to the volume of the tank, must rise one tank-dimension up, to replace the space previously occupied by the tank.

Now push the tank one more tank-dimension under the water. Does the water rise any more above the line? No. But does water rise? Yes. The volume of water equal to the volume of the tank, must rise one tank-dimension up, to replace the space previously occupied by the tank.

Now push the tank yet one more tank-dimension under the water. Does the water rise any more above the line? No. But does water rise? Yes. The volume of water equal to the volume of the tank, must rise one tank-dimension up, to replace the space previously occupied by the tank.

Now keep going, until you get as deep as you want. Every time you move the tank downward, an equal volume of water must move upward. Water moving in water is neutrally buoyant, true, but you are not moving this water with water. You are moving it by displacing it with an object of different buoyancy. Hence work must be input.

Ah, but they weigh LESS in the water than they do out of it. This difference is the Buoyancy. And it is due to the water displaced upward. The tank and its weights may be heavier than the water displaced--they have to be in order to sink. But the tank and its weights weigh less, by the weight of the water displaced, in the water than they do out of it.
How did you change the tank from being positively buoyant on the rising side, to negatively buoyant on the descending side? This cannot be done without doing work. You can't displace the water for free.

The lighter tanks rise, right? How do you think they do this? They do it because heavier water runs under them, displacing them upward. We see this as being a property of the light tank, but really it is a property of the water, which falls, to force the tank upward.
This process is reversed by the heavy sinking tanks on the way down.
Any work "done" by the rising tanks, is actually being done by the water falling into the space under the light tanks as they rise. And this work must be given back as the heavy tanks fall, raising water as they do so.

People that criticize things they don’t understand
Are people with big egos and little brains.