~ Sustainable Seafaring from Oceania. History, Design, and Relevance ~

August 09, 2016

Planing by proa...

I happened to be reading an article at Wikipedia about the venerable Sunfish and it mentioned that the design was one of the earliest production planing hulls (under sail).  So I followed the link to planing (https://en.wikipedia.org/wiki/Planing_(boat)

Was delighted to read, "The earliest documented planing sailboat was a proa built in 1898 by Commodore Ralph Munroe; it was capable of speeds of more than twice the hull speed. "

(The Commodore's boat had a flat bottom.)

In case you've never read about his boat here's an small excerpt and the link -



"With the growing wind on the quarter, outrigger in air and spray flying, they were traveling at a very high speed for a small boat. Then suddenly, with a little extra puff, the fore part of the boat lifted under them and, skimming the surface like a skipping stone, leaped into a surprising burst of speed. The sea beneath swept by like a cataract, vague and foam-streaked, the tugging steering oar cut a clear open cleft in the water and threw up on either side a long rainbow of spray, while the boat itself rested so lightly on the water that she made little, if any, disturbance in her flight. They stole hurried, ecstatic glances at each other. How fast were they going? What sort of creature was this proa? And what on earth was she doing?"

- from The Cheap Pages - http://www.thecheappages.com/proa/commodore.html#1900

  
On the subject of planing hulls - IMHO, while there's no denying that the deep-V'd native hulls are the most beautiful and offer the bonus of great lateral resistance for windward work, there's one advantage that a flat-bottomed hull will have and that is the ability to plane.  

Any finely proportioned hull, i.e. with a high length-to-beam ratio, will be able to go faster and faster as the driving power increases and there is no "hull speed barrier" so to speak, which must be overcome.  But while the knive-edged V hull keeps slicing through the water, a flat-bottomed hull will climb on top of the water and really go at that point.  It's a lot of fun!