Join Date: Sep 2011
Thanked 0 Times in 0 Posts
Rep Power: 5
Re: Fin vs bulb vs wing keels
I view the differences between these keel designs from a number of angles:
First is the performance issue to to change in resistance. Rather than calculate actual resistance, I can look at wetted surface. It is interesting to compare the wetted surface between the wing keel version of my boat (Catalina 400) to the fin keel version.
When I crunch the numbers, I find that the wetted surface of the wing keel version is less than 4% higher than the fin keel. Granted, the resistance is probably less; however this shows how little effect the wing keel has on the overall resistance.
A rough calculation of the difference between a bulb at the same draft, with the same righting moment, I would find the difference between the bulb and the wing to be a similar 4%.
One has to wonder if the 4% difference is significant. It might be interesting to look at some of the advantages of the wing keel versus the others. A quick look at Wikipedia gives a bit of insite:
Last edited by BryceGTX; 10-20-2012 at 08:17 PM.