Power boat hull


I’m trying to model a power boat hull, I’ve had a few goes at it but unable to get a desired result.
The bow cone is causing the most problems, I see a lot of boat models online simply join the bow to a sharp point, I would ideally like to add a round to the bow / knuckle. ( please see screenshots below)

I’ve tried a number of ways, mostly “surface from network of curves” the surfaces end up being very dense, so I’m thinking there must be a better way. I’ve also tried to split up the hull so I do the bow cone by itself but end up with ugly joins.

If someone could give me some tips on a better way to approach this model it would be greatly appreciated
Power-boat-hull.3dm (1.1 MB)


Ho Optimo, I’m getting in the conversation because I have an intrest in hulls as well.
Can you build the keel area as a separate part maybe with 2 rails and sweep with profile curves? Then possibly matching ? As far as density or complexity, maybe others can help there.

Hi Mark,

Thanks for your reply, I tried the 2 rail sweep on the bottom surface. Looks pretty good. I’m new to Rhino so I’ve had a go at “matching”. Does not work really. Maybe I’m doing it wrong.

sweep results below

Often times the best way to do those bottom surfaces is to extend the edges beyond the center line then get the knuckle shape by trimming that surface with the XY plane. Turn history on before trimming (or just do an intersection) and you can interactively adjust the shape by tweaking the edge curves.

It’s possible to get a much more natural surface that is not contorted by trying to resolve the corner of the UV net into the shape you want.

I find the easiest way to do a wrapper (or ‘cone’) is to mirror the bottom surface and then create a blendsrf between the two.


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Hi Optimo - if you have a hard corner along the keel, there will have to be a transition from the razor sharp to the roundy vertical someplace… It may be that starting that with a small transition between the halves of the hull at the keel will let you control it better. i.e. don’t make the keel super sharp/hard but provide a transition along the whole length.



Is this what you’re aiming for?

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Hey guys, Your comments have all been really helpful. Stratosfear, that looks great. So along the bottom you have split into 3 surfaces using 2 rail seeps ay?

You can use 2 rail sweep. I prefer using surface blend and rebuild to match the surface degree and point count to the secondary surfaces. Then I run dup edge curve and pull back to trim away the corner of the main hull surface. Then match the blend surface to it.

You don’t need to use netwerk surf to create this form. It just makes all these simple surfaces unnecessarily dense and inaccurate.

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Hi Stato, could you upload your model please?