How much does weight affect boat speed

[Hartly]

Hey all. A quick question. How much does weight affect the speed of a boat. I was out at Sylvan last week and had two extra girls on the boat. They each weigh approx 130 lbs each. My boats top speed dropped from 46 m/hr to 44m/hr. Is that normal ?

[Smoky buck]

Yes

[muzzy]

Weight slows boat down Im surprised with additional 260 lbs it wasnt slower

[Jawjacker]

Hey all. A quick question. How much does weight affect the speed of a boat. I was out at Sylvan last week and had two extra girls on the boat. They each weigh approx 130 lbs each. My boats top speed dropped from 46 m/hr to 44m/hr. Is that normal ?

Hey Hartly. I was at Cold Lake last weekend . I experienced roughly the same thing. My boat normally runs 40 m/h with my self who weighs 247lbs and my buddy who weighs roughly 250lbs. My son decided to come along and he weighs 259lbs. I lost about 2.5 m/h . I even swapped out props to the exact pitch but has vent holes and cupped fins. This coming weekend Im going to try out the new prop with just two of us.

[EZM]

Hey all. A quick question. How much does weight affect the speed of a boat. I was out at Sylvan last week and had two extra girls on the boat. They each weigh approx 130 lbs each. My boats top speed dropped from 46 m/hr to 44m/hr. Is that normal ?

No, that's not normal, at least not for a normally sized boat with appropriate power, usually your speed would be impacted far worse. I'm surprised you only lost 2 km/hr.

[Freedom55]

All questions are 'quick.' It's the answers that take time.

[tool]

If you need it explained it more direct terms,

FORCE=MASS X ACCELERATION

The force being constant (the output of your motor) if we change the variable Mass by adding two women to your boat acceleration must therefore be less and your boat just won’t go as fast.

Does that help?

[fish99]

elevation of the lake is the biggest loss of power you will experience . a 150 hp will be like a 115 , on a high mountain lake compared to a southern res

[Twisted Canuck]

You two are the reason I hardly post any more. All I’m asking is for some advice. Not to be made fun of or ridiculed. Thank you to everyone else. I appreciate your help. Moderators please close this thread. Didn’t know I was in Elementary school again.

Thread is closed as per request. I hope you did get at least some useful information to your question.