This has been posted over and over and it is still not true. Monohedron just means constant sections - no warp or twist. It could be flat, or super deep V, and still be a monohedron. a monohedron may or may not have a hump. My pontoon is also a monohedron.TomW1 wrote: ↑Tue Jun 15, 2021 4:48 pm Let's go over a couple of things first. As the NV has a monohedron hull so as it reaches planing speed it just continues on with its speed increase. There is no hump to break through that a V shaped hull has. The hump is not there. So any way here are some numbers I have come up with.
My boat most certainly has a hump in the performance curve - I have measured it, both in trim angle and in efficiency. The other DE and NV designs I imagine would act the same. Its not bad, and not nearly as bad as some heavier production boats, but it is there. The boat still has to climb its bow wave to plane off. It gets worse with increasing load. In order to make it really go away the boat would have to be truly semi-displacement design, which would maybe not be a monohedron form. And the Lcb would be further forward (like the Nina). Or be very light.
The trim and mpg are scaled to fit on the plot so consider them non-dimensional. The hump is the yellow curve bumping up, and the green curve dipping down. Other boats could be much worse, and mine may be exacerbated by the setback bracket.
Here's a (monohedron!) production boat (18' Bay Reef with Yamaha 115) for reference, with a bad hump (efficiency cut in half at dip vs. barely planing)
Based on fuel consumption, my boat would go 10mph with 25hp, as loaded for cruising.
Given that, I still would agree that a scaled down NV with 25hp would likely meet your needs. Maybe some other designs which were built around those requirements might do better (B&B OB20). At minimum if you want to sit in the NV trunk cabin you will need to raise the top a few inches, particularly after scaling. Same issue for standing under hardtop after scaling. Maybe raise the cockpit sole an inch or two also. I would draw it up to scale and see what it looks like.