Would a 15hp plane with 4 up?

[Welsh91]

Hi everyone, I’ve recently purchased a 15hp outboard. We’re pretty set on the Honwave t38. In your experience would 15hp be enough to plane 4 adults on calm seas? Most of the time it will just be the 2 of us but would like the option to cruise along with 4.

[Max...]

With a bit of jiggling of weight distribution and patience and if they are not really large then it will plane for sure but it's won't be the ideal power:weight ratio.

[Welsh91]

Originally Posted by Max...

With a bit of jiggling of weight distribution and patience and if they are not really large then it will plane for sure but it's won't be the ideal power:weight ratio.

Thanks for the reply Max. On power:weight ratio, do you think maybe we’d be better looking at a slightly smaller SIB? As I said majority of time it will be just the 2 of us.

[xpertski]

Originally Posted by Welsh91

Hi everyone, I’ve recently purchased a 15hp outboard. We’re pretty set on the Honwave t38. In your experience would 15hp be enough to plane 4 adults on calm seas? Most of the time it will just be the 2 of us but would like the option to cruise along with 4.

That should plane fine with 4 adults on the T38 (guessing its 3.8m). We had an Aerotec 3.8m with 15hp Suzuki and managed to plane with 4 adults, didn’t set the world alight with that weight but did get on the plane - easier of course in calm seas. Trouble is if you go smaller boat wise you might end up a bit cramped. If it were me I’d stick with the T38

[Fenlander]

We've used a 15hp like yours Welsh91 on a 3.4 Zodiac air floor, 3.6 Zodiac air floor, Honwave 3.5 alloy floor and the current Aerotec air floor.

When loaded up with 25l fuel, all the kit we carry (anchor/rope bag plus 3 dry bags) and two sturdy adults plus two lightish teen girls and dog the two air floor Zodiacs were OKish but the 3.5m Honwave and Aerotec not great.

Of the two Zodiacs the 3.6m was best... hardly any heavier than the 3.4 but the longer fairly flat undersides seemed to help.

So going smaller unless it saves loads of weight isn't always better.

With 4 adults in the 3.8 Honwave and your 15hp you are right on the point of might be just OK... or not that brilliant. No-one will know for sure until you get it on the water and find out.

One of the things we all judge differently is "getting on the plane". For me it's about the ability to get on the plane promptly at will when on and off the power in a difficult sea without folks in the boat needing to move to get it over the hump.

However for folks who perhaps do longer distances at one speed on flat water it might be acceptable to have two crew move forward for a slightly extended over the hump period then re-balance once on the plane.

Usually those 15hp motors come with a 9" pitch prop (I'm fairly sure) which suits most circumstances but if crew load is high you can pitch down to get on the plane easier but sacrifice top speed a bit.

[Max...]

Stick with the solid floor 3.8 if four up. Anything smaller is too small. It will be ideal with two but with four a 20 or 25 would be preferable but that's a huge step up in weight and bulk to carry.

Again, if it is 90% of the time just two then a 3.4 airfloor (or 3.8 Aerotec) would be ideal matched with the 15. As always we're back to the 'which SIB' sticky but you have to choose according to 'your' specific needs (location/crew/storage/launch site/use) and then it come down to (airfloor) = lightweight/portable/easy setup vs (hardfloor) = heavy/slow setup/less portable but gives 'real' boat feel and better performance.

[Max...]

duplicate...

[jonp]

You could change the propeller pitch to a lower pitch if it doesn't. I have two different props for carrying different loads. A lower pitch is like dropping down to a lower gear, just like you do in a car or heavier loaded vehicle.

[jeffstevens763@g]

Agree with all prop it down for four then prop up for two stick with the 3.8

[plymjack]

Well I have a 4m and the 10HP would not plane 4 up but having changed to a 20HP it does quite easily so would guess that as has been said with the right load distribution the 15HP should be OK.

Interested to hear about prop changing, not thought much about that - will see whats available and see if its worth while for me.