Airplanes deploy revers thrusters when landing which are basically just shaped metal shields that move into place behind the engines to provide reverse thrust and slow the plane.
But adding a fan on a sailboat is seen as stupid and doesn’t work.
Airplanes deploy revers thrusters when landing which are basically just shaped metal shields that move into place behind the engines to provide reverse thrust and slow the plane.
But adding a fan on a sailboat is seen as stupid and doesn’t work.
A fan on a boat would work. There are these fan boats people ride through the Everglades. There are propeller sea planes. The difference to a sailboat is the profile of the vessel under water. A sea plane has two or three smaller areas that are submerged. The everglade ones are just breaking the surface of the water and are very flat so they can glide over water and plants. A sailboat has a big, often deep profile under water, the whole length of the boat, possibly a keel underneath. And that’s moving through water, which is thicker than air. So you need possibly more than one propeller and the engine may need to give you more horsepower to move the boat through water with the force of the air above deck. That’s inefficient so boats tend to move their propellers under water.
A few container ships have a spinnaker sail they can deploy. If the wind is favourable they can reduce the engine output and save diesel. Just in case you’re wondering about the reverse situation.