Why are propellers on the front of planes but the rear of boats?
The original thread on r/explainlikeimfive is here. Questions asked by u/Tomoyboy
Historically plane propellers were attached directly to the engine via the propeller shaft. You would not want to have something heavy in front of the boat, because if the boat is steered into high and aggressive waves, the boat would go through the wave rather than riding it.
Another reason is simply protection, planes travel in the air, so the only risk of damage is a bird strike or dust particles. In boats, however, the propulsion systems of the boat would be damaged if it encounters an underwater obstacle or a floating object.
Getting onto the nerdy side of things, in terms of physics, the answer is simply hydrodynamics. In order to pass cleanly through water, boats need to have a narrow point of entry — a V-shaped hull — in front. Speed boats are designed to actually rise the bow out of the water — which would lift fount mounted props out of the water.
Planes themselves can have propellers at the rear. It is more common for them to present in the front so that the engines can get clean, undisturbed air. For engineers, it is easier to balance the weight with propellers in front rather than at the rear.
Here is the thread to r/explainlikeimfive question :
