Bouyance engines - scam?

codwell

Bouyance engines - scam?
« on January 11th, 2017, 11:51 AM »
There are lots of videos with this type of engine.

https://www.youtube.com/watch?v=8Zenn0VD2Bo

This is the biggest one I saw so far:

https://www.youtube.com/watch?v=Ux1FuwCnAn4

And a different type with 2 capsule which lifts up and down:
http://panacea-bocaf.org/hidrofreeenergysystem.htm

https://www.youtube.com/watch?v=qQIhLys51Gk

The question is, does the energy required to power the pumps blowing in air to the bottom of the container is lower than the energy provided by the upward motion caused by air in water. We need the math, maybe someone can help. If all of these are a scams, then it's really sad that how many people invest money to fraud people.