Buoyancy and reverse-submersion technique(s)

[LValfre]

Hello guys,

I've been toying with some ideas in my head about a project I'm working on. I want to make sure I'm doing this right. FYI, I'm not a physicist but a business major with a knack for science/math.

Is it possible to 'inject' a buoyant object into a body of water from under the water line?

For example, a pool with a drain in the center. If the drain could be opened and closed, would there be a way to keep it closed and then open it to float something through it?

The only idea I've had is to have some kind of bottom loading bay. You can seal off the body of water above from the sublevel 'loading dock', effectively creating 2 systems of water. When the bouyant object is in place in the bottom system, release the seal so all the water falls down into one system. It should float to the top right? What if the object completely filled the bottom bay volume wise. You could still drop the water and make it a system so the object could float, right?

Thanks for any comments ahead of time, i really appreciate them!

 

[gtoguy97]

Yes, it is possible to inject a buoyant object into a body of water from under the water line. Generally, it is done by using a device called a 'pump-jet', which is able to pump out water at high pressure, pushing the buoyant object forward. Alternatively, you can also use a compressed gas system or a vacuum system to achieve a similar effect. In all cases, the object must be sealed in order for it to float up once it is injected.