a more sinister reason
In Mazda’s case it coincided with inflated horsepower ratings. I believe Mazda actually had to offer a partial rebate for the false info.
OTOH you have to like it
Margin of error in my speedo plus margin of error on a radar gun is what allows me to travel at 10 mph over on the freeway (OR at least CONVINCE me that I’m going that fast…)
Not linear
I think a more accurate statement – and what Charlie probably meant – would be “some rocker can increase speed”, not “more rocker always increases speed.”
Hull design is always a tradeoff. It’s easy to say “all else being equal…”, but in reality, it’s very difficult to change just one parameter/dimension and keep everything else equal.
The goal is to
Minimize wave making and drag due to friction at speeds that are high enough to matter (e.g., where the paddler has to really paddle to achieve). I have a very simple and unproven theory about the bow rocker: just like we want a full plumb bow that widens as slowly as possible when seen from above, I think we also want that same shape to be present when seen from the side. Basically, a very sharp half-cone as the bow, with the tip at the water surface would probably have the least resistance. And that means rocker has to be present since in the middle of the boat (or thereabouts) there would be several inches of draft, to provide the design displacement. So, the boat should have about 3" of bow rocker… Of course, such a shape will not have very good tracking, and unless one sits on the bottom of the rounded hull, will have little stability too…
CEWilson has done it again
I wish he’d stop confusing these issues with fact. I am so much more comfortable with those who begin with “I believe” (I always need to look up when reading this), “I think” (Nice to know you’re awake.), so here I am with Charley, and actually learning something once again.
Thank you !
You didn’t read the thread
Rocker is not the only thing that determines speed.
Rocker relates to wetted area and that relates to friction.
Wrong…
I did read the thread, actually.
It’s just that some of things said in it don’t seem to make much sense. Or maybe need further exploration in order to do so.
And yes, I know about wetted surface area and its impact on speed, particularly at lower cruising speeds.
(Of course, not everyone paddles at lower cruising speeds…)
“Fitness” paddlers
It’s like “fitness” bikes. Those users are not typically going that fast/hard.
re: ‘Fitness’ paddlers
"It’s like “fitness” bikes. Those users are not typically going that fast/hard."
That seems an odd (over-)generalization to make.
I myself am part of a bike club, and plenty of ppl in it go like hell, all the time. It’s not terribly uncommon behavior.
Perhaps you’re confusing the guy who rides solo on the MUT on the Wal-Mart special he picked up to “get in shape”, and all the testosterone-addled youngsters on their $3000+ carbon-fiber racing steeds.
There’s riding, and then there’s RIDING. And there’s plenty of the latter.