Fastest of the fast?

[Byronmaui]

I forgot but Stuey if you don't win the molokai then I will blame the board because you have one of the top motors (Woogie) in the business.

Aloha

Byron

[Tree]

Hehe...the "challenge" hasn't even been ironed out yet. It would be great to have an open race but get the challenge part over with 1st.

Yeah how about a change of venue... Say Gloucester to P-Town during a Noreaster in December?  Bring your Drysuit. 

[stoneaxe]

Because it would be a hell of a lot more fun Mailiko to Kahului in board shorts and sunscreen....

We'd have to go P'town to Gloucester in a Nor'easter anyway.... .

[stoneaxe]

Way to go Rand. But don't go giving MY room away... . If this happens by hook or crook I'm going to get out there!

[Byronmaui]

While me and Stuey work out a game plan I thought I would throw out my math problem....

7 mile flatwater course no wind or swell

Rider #1 18 footer SUP and averages 50 strokes a minute through out the whole 7 miles

Rider #2 12'6 SUP and averages 75 strokes a minute through out the whole 7 miles.

Both riders are equal height and weight. Who wins and why? Can we predict the winning time or finishing times with all of our math or is this a lost cause?

Aloha

Byron

P.S. Math was weak in highschool and college but my dating was strong.

[PonoBill]

Dating is generally more important than math, though math doesn't get you into as much trouble.

Really, no wind or swell, it would be hard for a 12' board to beat an 18 foot. the guy on the 18 could loaf along while the guy on the 12' paddled his guts out. There's some graphs around on the kayak sites that show energy expended per KPH. You can easily see when hulls get close to the max speed. The curve bends over sharply at about 70 percent of maximum speed and goes almost flat at 90 percent. Gaining that last ten percent takes a huge increase in power.  Maximum hull speed of a 12' is 4.64 nautical MPH. Max speed of a 18.8 is 5.8 nautical miles per hour. The effort curve is not linear at all. At 70 percent effort the 18.8 is going as fast as the 12' at 100 percent.

Even if the curve were linear, at 80 percent the 18.8 would be going the same speed as the 12' at 100 percent.

But all this goes out the window in chop, swells and confused seas. then a great paddlers smokes the competition--no matter what they are on.

[Admin]

7 mile flatwater course no wind or swell

Rider #1 18 footer SUP and averages 50 strokes a minute through out the whole 7 miles

Rider #2 12'6 SUP and averages 75 strokes a minute through out the whole 7 miles.

Both riders are equal height and weight. Who wins and why? Can we predict the winning time or finishing times with all of our math or is this a lost cause?

I have an add on question for those who might know.  This stuff is interesting, but I have all Q's and no A's.

There was mention that this was based on waterline.  So if the waterline on an F-16, due to relatively high volume and its heavy entry rocker is say 13.5 feet long (guess) and maybe it's almost all of the hypothetical 12'6 under the weight of the same size rider, wouldn't the waterline lengths be way closer?

It seems that some of the long Cali boards that we are seeing are so low rocker as to be almost 100% waterline (even with no rider onboard) while some downwinder 17's have 2-3 feet that only will have water contact when swell riding, or under the weight of a really heavy rider.

Also, what about width?  Does a 40 inch wide 18 footer still take less effort than a 26 inch wide 12 footer, even with all of the extra drag? 

[PonoBill]

Great questions. It is indeed the waterline length, and a lot of rocker will shorten that. When Mark was building the first F18 it was for Cali, and he did it with minimal rocker for exactly that reason. The width is an interesting issue on it's own. Sailboat races are always grouped by waterline length, and back 20 years or so some of the smart builders were making the boats very tubby in the middle. When the boats were measured up straight, next to the dock their waterline was 26 feet or so, but when they heeled over the waterline was a curve, and it extended up to 30 feet or more. they kicked ass in the races, but they needed a lot of sail to go fast.

The shape of the hull and how it enters the water determines how easy it is to get up to speed. We've probably all experienced how hard it is to get a wide board with curved rails to glide. Straight rails and a fine entry make it easier to approach max speed, so there's all kinds of things designers can do to make the boards faster.

And then there's designing for conditions. I think a flat bottom 18 footer would be a submarine on a big swell day at Maliko. You'd want to never get in the bottom of a trough.

[stuey c]

Great questions. It is indeed the waterline length, and a lot of rocker will shorten that. When Mark was building the first F18 it was for Cali, and he did it with minimal rocker for exactly that reason. The width is an interesting issue on it's own. Sailboat races are always grouped by waterline length, and back 20 years or so some of the smart builders were making the boats very tubby in the middle. When the boats were measured up straight, next to the dock their waterline was 26 feet or so, but when they heeled over the waterline was a curve, and it extended up to 30 feet or more. they kicked ass in the races, but they needed a lot of sail to go fast.

The shape of the hull and how it enters the water determines how easy it is to get up to speed. We've probably all experienced how hard it is to get a wide board with curved rails to glide. Straight rails and a fine entry make it easier to approach max speed, so there's all kinds of things designers can do to make the boards faster.

And then there's designing for conditions. I think a flat bottom 18 footer would be a submarine on a big swell day at Maliko. You'd want to never get in the bottom of a trough.

I really love all these questions and discussions you guys have and I just can't stop myself from logging in and reading........no wonder the sport is light years behind in Australia! Would still like to contribute but as you may understand due to recent events am a little timid. I'm gonna build and send you guys a Penetrator for testing damn it, even if it has to be a goodwill gift for all you have done and are doing!!!!!
                         All the best, guys, Stuey Campbell

[Tom]

The shape of the hull and how it enters the water determines how easy it is to get up to speed. We've probably all experienced how hard it is to get a wide board with curved rails to glide. Straight rails and a fine entry make it easier to approach max speed, so there's all kinds of things designers can do to make the boards faster.

I think this is why so many of the top SUP shapers have a windsurf design background. These are design issues they had to deal with because of the different conditions a sailboard has to perform in. Not to take anything away from the surfboard designers.

[Shnoover]

Stuey- Brush the haters off...  I think Snoop Dogg said that.  Anyway, good natured ribbing is ok anytime there is a basic level of respect.  I am not from HI or a physicist (I'm a chubby white guy - probably shouldn't quote a rapper either), but I think the video shows you know how to make a board.  Don't stop the participation.