Centerboard

If you can minimize the water resistance, and the wind and waves are just right, you can really get going.

In 2006 here in Maui (a month after getting my AI's) I got just the right conditions one day with many fast runs many 22's & 23's and finally a 28mph run on the GPS. Fastest seems to be when the wind created long wind waves (miles long). I just sailed along the tops of the waves, with less water resistance. I later found the readings were a little high from the gps bouncing around (I didn't have it mounted yet). I also found on returning home that a Small Craft Advisory had been added after I had left for my sail.

I no longer try that as I've had discussions about what would happen if something broke at that speed (thanks dear).

Above about 10mph the hull hums from planing.

Since the beginning of 2007 I've kept a log with statistics.

09/22/2007 - Three of us were sailing a beam to broad reach doing 8-9mph when a VERY strong steady gust came for over a min. pushing all three of us (in formation) to 19.7MPH! We could see each others boats but couldn't see each other because of the spray off of the hulls reaching at least 1/2 the height of the mast!

That's my two big wind stories, On sailing trips (not fishing) I try to break 10mph. In good conditions I average over 5mph including drifting during snacks and lunch.

My log is posted here:https://sites.google.com/site/kayakingbob/Home/sailing-log-1

2009 has been a slow year so far for getting out sailing, between extremes in winds (too little to sail or small craft warnings), My sailing partner getting a knee replaced, his wife (3rd AI) with back problems, and then a long trip "off island".

With a new GPS I bought on my trip I can now even save and show the "Track" of each adventure! (click on "Track", for either of the top two newest entries in my log)

Enjoy, go fast, but be safe!

Matt, thanks for clarifying the definition of daggerboard and centreboard. Hereafter, I will only refer to it as a centreboard (centerboard in American).

I'm think'n that the turbo blades would have to give better resistance to sideways slip than the dagger anyway. I just roughly measured the surface areas of both and the 2 tubo blades combined have about 20% more surface area than the daggerboard. So, I'm think'n that if you do have sidways slip, the only advantage of using the dagger over the drive is that it's quicker to install. When sailing with the drive in place I always have the blades vertical, but I'd like know though what has more drag, the drive or the dagger.

My understanding of aircraft wings (and sails) is that they have to be asymmetrical to generate lift - the Bernoulli principle.

Since the thingo-board is symmetrical, wouldn't it's only effect be the lateral resistance it offers and wouldn't that be simply a function of it's surface area?

This seems to be the opposite of sailing logic.

On most boats (and I believe this includes the AI) you want the dagger fully down in lighter air and reduced as the speed / wind increases. You can sweep the board aft in higher wind.

Its a bit like airplane wings... slow planes use big, fat foil wings. Higher speed aircraft use shorter, narrower and thinner air foils.

Matt, I can't see how the centerboard being vertical or pivoted to horozontal can make much difference to the performance of the AI. The surface area is the same no matter what position it's in, and it's not that the board is profiled to act like an aircraft wing. It's just a board. I can see how the AI would turn better with the daggerboard vertical as the AI is pivoting around the board, but whether the board is vertical or horozontal, the amount of side slip would be the same wouldn't it ?

P.S. I prefer to call it an off-centerboard

And, if you are sailing close hauled with the drive in, then we are not even talking about the same thing. You already killed your upwind performance so much with the drive. And, if you are pedaling it, then we aren't even talking about real sailing but rather "motor sailing."