The Unsolved Mystery of Future Submarine Design

The key again is these vortex rings, these swirling circular donut shaped currents. If we can come up with a submarine design that could create those, but that doesn't require the very flexible motion of a natural jellyfish then we found that that actually could be an important value added to current submarine designs. We've tested this in the lab. So what you can do is take a conventional propeller driven submarine and add a mechanical attachment at the back - it creates a choppy or flow. You were able to show that that vehicle could be 30 or even 40% more energy efficient than the same type of vehicle without that pulsation in the flow.