[BobLemoine]

That being said, another way to get the ESTIMATED MINIMUM HP required to plane a boat. This is assuming your weight is accurate, and you are dealing with a flat-bottomed boat in still water. It is very simple. Take your boat weight and divide by 50. So, a 1000 lb boat (boat, motor, gear, passengers), flat bottom or still water would take 20HP to plane.
If your boat with all gear is heavier, it will take more HP to plane.
If your boat has a v-hull, it will take more HP to plane.
If your boat is in rough water, it will take more HP to plane.
Note: this is only to plane, not run around at 30 MPH. here

[mybassfishing]

Re: Boat weight to HP ratio ? [links]

[KathYR1985]

Re: Boat weight to HP ratio ? here

[OneFixt]

Now, if you know the weight and the hull type (i.e. constant), you could use that same calculator in reverse to give you an indication of the power needed to move the boat at a given speed.

[ben-abuya]

the Coast Guard guidelines is the best way to go. here

[azazar]

1 HP is approximately equal to 750 watts….How many watts is a 3hp motor? [links]

[lancommy101]

The Rigid Hull Inflatable Boat is a high-speed, high-buoyancy, extreme-weather craft with the primary mission of SEAL insertion/extraction and a secondary mission of marine interdiction operations. The RHIB is also used by U.S. Navy sailors for visit board and search operations at sea.

[Celine]

(6) 1436 G3 with 8hp merc tops out 16 to 18 mph.

[YeahR]

Most outboards have a preferred powerband where they run at optimum efficiency and minimal fuel burn. Yep, that 75 hp might be able to push the boat to 32 mph, but that’s with the throttle jammed against the stops. [links]

[mr1337357]

Top 10 Best Inflatable Boats in 2021 here

[dingus]

Honda BF2 Four-Stroke ($920; www.honda-marine.com) power: 2 hp weight: 29 pounds top speed: 5.3 mph noise at full throttle: 95 dB-A. The Honda BF2 employs a centrifugal clutch, which allows the engine to idle without moving the boat and automatically engages the prop as the RPM rises.

[chrisdbc]

50 hp is not gonna do u too well on that big boat. Like mentioned above you won’t be pulling any skiers or tubers. or anything really. I would get u a 90 hp for it.

[zoidial]

A speed test on a Mako 181 with a 50 hp 2 stroke Mercury. 28.3 MPH. here

[bitplane]

A 9.9 outboard will push a 6500 pound Catalina 27′ sailboat at 6-7 knts. more

[Francises87]

That can be anything from 1 km/h (0.6 mph) to 300 km/h and above (200 mph). I have personally driven several vehicles that just by chance were powered by a 90hp engine. VW Golf, I would drive it routinely at 180km/h (110 mph) but it could go a bit faster.

[TORNS]

5800 RPM. I had the same motor on an 18.5′ Sea Ray and it ran [links]

[Kay]

Me and just the boat it will hit 32 mph on glass days. 2 guys and gear takes it down to about 20 to 22 mph.

[Confiscative]

When buying a pontoon boat, one of the major considerations is your top speed. Since pontoon boats are generally not built for speed, skiing and tubing behind one can be difficult unless you take care to select an engine, weight, and pontoon style that will be conducive to speeds required for skiing and tubing.

[Regent]

If you are new to boating, that is probably a little eye-opening. Before, you thought you needed as much speed as possible, but as you can see from this breakdown, the optimal speed for most watersports is only 22 mph (36 kilometers). Just about ANY pontoon boat with a 90hp motor can do that as long as it isn’t loaded down with people. With a 115, you should be hitting the optimal speed even if your boat is pretty well loaded down with people. For most pontoon boat captains, the real goal is to hit the golden 22 mph (36 kph) mark. At that point, your fishing/cruising rig becomes a nice watersports rig as well. here

[komoto]

Your initial response is probably “the faster, the better” but in reality you likely don’t need to go as fast as you think. While speeds certainly vary according to the tastes and abilities of your riders, consider the following as good average speeds for various water sport activities. more