It’s a sunny day at the seaside. A high-powered jet ski whizzes across the sea, a jet of water shooting high into the air behind it, pushing it along. WRONG! That jet of water is NOT what makes jet skis go. They need a lot more power than that little spray. (Underneath they have a high-speed prop or a much more powerful underwater water jet.)
That small jet of water – the ‘visibility spout’ or ‘rooster tail’ is mostly just to look cool, although it makes the jet ski more visible, and useful for a small craft. But you can actually power a boat – or jet ski – with a big enough spray of water into the air. Here’s how…
You’ll need a boat hull 40cm or more long, the longer the better, something that can be loaded up with 1,000g without water above its Plimsoll line. You’ll also need a solar fountain – the type with a separate solar panel is best so that you can balance up the boat while putting the water spray near the stern.
...