Originally Posted by David M
I don't know but it seems someone needs to check their facts. The only way you could stop the flow around the hull
is if you could compress the water. Water must move aft as a ships displacement
moves forward, with respect to the surrounding water.
The other question is, how much energy is it going to take to run all these pumps? Is it more or less energy than the energy saved by having this system?
The third question is, what sponge material stops fouling?
I don't know if it could work or not, just asking some obvious questions which were not addressed.
All your questions are valid except one where I think you just missed the explanation.
The pumps would compress the water, well, not much, but put it under pressure so it would move more water in a small tube.
So, at a point forward on the hull where it would normally have to be pushing water aside, the pumps would remove that water. Then in the back, at a place of low pressure, the water would be re-intorduced. So, a steady pressure would be maintained everywhere on the hull.
This, of course, would be massively complex. And, at least with todays technology, totally impractical. But, in theory, it would work.
That is, it would work except for the other points you brought up.