Pump-jet

Hey buddy, have you ever seen a boat or a submarine moving in the water? They usually have a long stick called a propeller that spins around and makes the vessel move forward.

But have you ever heard of a pump-jet? It's a cool device that works like a propeller to propel boats and submarines through water, but it doesn't have any exposed blades!

Instead of blades, a pump-jet has a big tube surrounded by curved blades called stators. At the front of the tube, there's a little hole where water comes in from the front of the vessel. Then, a motor inside the tube powers a pump that pushes the water through the tube and out the back at high speeds. This creates a powerful jet of water that shoots out, and that's what propels the boat or submarine forward!

Since the blades are inside the tube, it's much safer for marine animals that might get too close to the boat. The pump-jet is also more efficient than traditional propellers, which means you can go faster or farther on the same amount of fuel.

So there you have it - a pump-jet is a cool device that helps boats and submarines move through the water using a powerful jet of water.