Question from a newbie-Why are sailboat engines so small HP wise ? Is it size as earlier mentioned ? Or just a desire to not move quickly ? I think it's great cost wise as motors are through the roof costwise but as a power boater it made me wonder.I currently have 3 boats and the smallest is a 16 ft wooden boat skiff I built with a 25 hp outboard and I'd honestly like to upgrade that,seeing these big sailboats with 9.9s and 15 and 20 hp has me stumped
Is it their weight of the boat or the design that makes it a displacement hull ?Hey,
It's really very simple: Sailboats have displacement hulls. Meaning that a sailboat can only go so fast (and not very fast at that). The length of the waterline determines the top speed. My O'day had a 29' waterline length and hull speed of about 7.2 kts. The stock 21hp engine could push the boat at that speed. If I put a 50HP engine in it still would not go any faster. Even a 500 hp engine wouldn't help the boat to go any faster. A bigger engine would just make a bigger hole in the water since the boat can't get up out of the water but must push the water aside.
Most powerboats have planing hulls. Meaning that the boat can get up out of the water and ride on top of the water. A planing hull is not limited in top speed, so more HP = faster speed.
In reality, a sailboat can exceed hull speed, but not by much and a bigger engine maybe helpful in conditions like high winds and waves. But the difference is pretty small, like a 30HP engine instead of a 24 HP one.
I've seen those McGregor boats,is that similar to what you're talking about ?There are (or at least were) a few designs that could get up on a plane, if fitted with a big enough engine. For sailboats they are pretty good powerboats, and for powerboats they are pretty good sailboats. But either as purely a sailboat, or purely a powerboat, they're nothing to brag about.
Yup.I've seen those McGregor boats,is that similar to what you're talking about ?