Laughing... I have Phil Bolger's book, "Boats with an Open Mind". After looking over some of the designs, I told my wife what my mother used to say a lot when I was young--"Don't be so open-minded that your brains fall out."
It may have happened despite her warning. Dave Shaddock -----Original Message----- From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of tim ford Sent: Wednesday, February 06, 2008 2:00 PM To: [email protected] Subject: Re: catalina27-talk: Kort Nozzle YES!!! The Dol-Fin...I remember the teeny ads in the back of mags like Small Boat Journal!!! I can still see little half-tones of the beasts in my mind, burned into my brain like neurological fossils from some graceful, simpler time of Phil Bolger designs and Edey & Duff gunkholers. Wait...did I just use the word "graceful" in the same sentence with "Phil Bolger?" tf no fatty knees David Shugarts wrote: > > There is a certain unavoidable dichotomy about this. I cannot see how a > racing sailor would want it, but a cruising sailor would probably really > like it (depending on his waters). We grow a lot of marine flora and fauna > here in Connecticut, and I wouldn't want it, whether racing or cruising. But > wherever it could be kept clean, it would make a serious difference in > thrust, at a cost in drag (especially under sail). > > Similarly, there is an even simpler device said to give certain beneficial > effects to an outboard. Back around 1987, I was editor of Powerboat Reports > and we decided to test a device called the Dol-fin. I don't know whether it > is still available. Essentially, it is like adding stylish wingtips to your > anti-cavitation plate. There were various claims of fuel efficiency, speed > and control, I believe. As I recall (20 years ago now) there was no > appreciable difference in any parameter when we tested it in real-life > conditions. You were trading off some well-understood aerodynamic (er, > hydrodynamic) benefits versus wetted surface (wetted surface always means > drag). > > --Dave S. >
