Prospector Rocker???

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Stev00
Posts: 2
Joined: Wed Mar 21, 2012 1:15 pm

Prospector Rocker???

Post by Stev00 »

I am building the Prospector boat and have questions regarding the rocker:
1. The plans specify a rocker of 2.75" @ 90% of DWL. Ok, what is the length of the DWL?
2. Bill Mason, in his book Song of the Paddle, says he prefers a rocker of 4", yet the rocker of Bear Mountain Prospector is only 2.75". Why the difference?
3. If I want to increase the rocker how do I go about doing it?
willo
Posts: 156
Joined: Sun Jul 15, 2007 12:48 pm
Location: Echo Bay ON.

Re: Prospector Rocker???

Post by willo »

The length at the waterline should be shown on a set of plans. My understanding of how rocker is measured is something differnt to different people.I would be cautious changing it from the plans. It has more rocker than the Ranger and I would not want any more than that. Bill Masons measurement is double, but it may not have been measured the same.I am not a designer , so this is just my opinion. To increase the rocker all the stations but the stems would be raised above the base-line of the strong back with more height as you move in toward the center.
Steve Killing
Posts: 30
Joined: Wed May 12, 2004 3:16 pm
Location: Midland, Ontario, Canada

Re: Prospector Rocker???

Post by Steve Killing »

Hi All,
I think we have very close to the same rocker that Mason quotes. There is, unfortunately, no standard way to measure rocker. That is why I decided to publish how we measure it so at least all the Bear Mountain boats will be quoted with a given standard and if you want to compare with other boats you can use the same technique.

The rocker, which is the curvature of the bottom of the boat as viewed from the side gives an indication of how easily the boat will turn (high rocker) or track in a straight line (low rocker). I found that if you include the curvature in the last 10% of the waterline length it can influence greatly the answer, but have little effect on the paddling characteristics. Perhaps the easiest example to think about is a canoe with what I would call “zero rocker” (a straight line keel), but the bow and stern were immersed 3" - some people would call that 3" of rocker, but with our system we would call that zero rocker.

My conclusion is I think the Prospector has lots of rocker and a huge volume inside - so my vote would be to leave it as is. I hope that this has been helpful.

Regards,
Steve Killing
Stev00
Posts: 2
Joined: Wed Mar 21, 2012 1:15 pm

Re: Prospector Rocker???

Post by Stev00 »

Thanks for your replies. Yes, it is pretty hard to ask Mr. Mason now. I have decided to take you advice and not increase the rocker. Thanks again.
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