Boats that plane with 6hp?

[Buz]

Will any boat here fit this plan?

I have a 6hp XL shaft kicker on a 18ft deep-V that I intend to use more often on a smaller boat I'll build for fishing shallow NC coastal marsh. I've got five miles of creek to get to salt.

5 miles at 15 mph is 20 minutes, and 1 hour at hull speed. A two-hour round-trip is no good.

Now for the kicker. I hope for a boat able to plane with that 6hp, not only with my 140lbs, but a buddy's 200, too. That's about 450lbs for two people, motor, gas, tackle.

SC16 sez "planes with 2, 350lbs". That must not be displacement weight as that leaves no weight for the boat. And CapeMan's goes 9mph with 2hp. (Wow)

Speeds/weights in all boats' plans seem to say I'm not planing with both of us and our stuff, but I can alone.

Think I'll need a 10 or 15hp, too?

[cape man]

My SC16 was not built to plan, losing all the interior seats and braces, and using 4mm ply throughout. I hung caned canoe seats, all to keep it below 100 lbs to allow car-top carrying. With two of us and a cooler it almost planed and they clocked us at 9mph on her maiden voyage. Alone, my son was able to get it fully up with a tiller extension and sitting forward on the deck. No speed recorded, but watching the video it was going somewhere in the mid to upper teens.

Your 6 hp should get it on a plane with 2 and gear, but you'll need to build a higher transom to accommodate the long shaft, which will add to the torque, and require more bracing than I did for my 2.5 hp!
Build it, and if the 6 doesn't work get a larger engine.

Check out Coach's SC16.

[cape man]

viewtopic.php?t=63888

[Buz]

Thanks for the link. I'd seen his boat referenced but hadn't seen the build thread yet. Read it last night and bookmarked it for reference along with your's.

I intend to do without the seats and decks, much as you did. But I'll skin both sides of 6mm, put on stiff rubrails, and maybe low stringers and/or a skeg or three. Think I'll add tape at the chines, too, as I can see the possibility of a 10hp in the future. You never did need that thwart you carved?

I wonder if Coach is still around and would be willing to share those changes he made to the bottom dimensions.

[Buz]

The D15 is flatbottomed, lighter, and only a couple inches wider.

Ya think it would plane as easily as a SC16?

[TomW1]

The D15 will not plane as easily as an SC16 do to the design differences, but that does not mean you cannot build it as light as you describe and try it with the 6HP. Nothing tried, nothing gained.

Tomdi

[Buz]

Thanks for stopping by.

At less than 150lbs it seems like that thing would be all but planing just sittin' there.

[Buz]

Thanks to all who have devoted time to help me here.

Turns out, this part of my fleet will be filled with a 15ft Gheenoe with a rashed-thru(!) keel and hull plane dips that'll need repair, and of course, a new higher transom. Any discussion about that will be in the CL forum.

This allows me to move right ahead into building a nice-day 30mile-out boat. My present 18footer has too little range (and , I guess, length) for my area.

[Matt Gent]

Planing with 2 adults on 6hp takes a light and narrow boat. A buddy built what is basically a 1532 plywood jon boat. It weighs under 100lb hull only. Solo it goes about 18, 2 adults about 15, and 4 adults (avg 150-160lb) 11-12mph.

My flivver, 8'x4' also runs 18mph solo but won't plane with 2 of those 4 adults. Too short and wide, can't climb it's own bow wake.

The little jon boat has a slight rocker in the hull, and has zero transition to planing when the weight is distributed properly It's happy to run at any speed.



https://www.youtube.com/watch?v=-s2h9d7j5Vk