With the FPB 64 out of the clutter of the building hall we thought you might like to see few photos of her hull shape. We’ll start with the bow.
Waves react to the bow’s distribution of volume. This means all aspects of the three dimensional shape. You have to model the sectional view that we are looking at here, and integrate it with the plan view (top down), while considering how the boat will steer in port and in surfing conditions.
A “sharp” or knifelike bow can be more comfortable upwind, but at a cost in comfort and control with the waves behind you.
Part of the way you mitigate the tendency to bow steer is by cutting away some of the forefoot area. A shape like this also rides over logs and ice more easily than a deeper shape.
And of course this is all balanced by what is happening in the stern. Too much volume aft and the seas on the stern force the bow down: a wet, harsh ride results. Too little stern volume and drag increases beyond very slow speeds.
But if you get the relationship between bow and stern right, a lovely, easy motion is the result. We’ll know soon how the FPB 64 does in this regard.
Posted by Steve Dashew (March 19, 2010)
March 19th, 2010 at 9:12 pm
Steve, et al.,
Congratulations on the launch! Boat looks great, I hope the sea trials prove as successful as the first couple runs appear to have been.
In looking at the ‘fins’ pictures, I wonder what the official reasoning is behind the white paint? Easier to see / keep clean comes to mind, and I imagine it’s a hard (maybe slick?) paint?
Also, I see PropSpeed on the wheel, have you been using it on WH?
Thanks, enjoy the best part of the project.
-c3
March 19th, 2010 at 9:10 pm
Hi Chris:
The fins are painted white for two reasons: they get quite a bit of sunlight on them (compared to the hull bottom) and black paint in the sun grows a garden much faster than white. The second reason is visibility, it is easier to see kelp or other debris on a white fin.
We used Prop Speed for two seasons on Wind Horse and then switched to Prop Shield as a test. They seem comparable, and both are much better than an uncoated prop.