RE: [Paddlewise] Hull speed

--- Bob Denton <BDenton_at_aquagulf.com> wrote:
> >>>
> -----Original Message-----
> From: owner-paddlewise_at_paddlewise.net
> [mailto:owner-paddlewise_at_paddlewise.net]On Behalf Of Nick Schade
> Sent: Thursday, March 08, 2001 9:19 AM
> To: Paddlewise
> Subject: Re: [Paddlewise] Hull speed
> 
> 
> One method which would be quite easy although not as accurate is to 
> paddle with a heart rate monitor and a speedometer. 
> >>>
> 
> I ride the same 10 or 15 miles every night after work on my bicycle

Wow.  That's dedication, or something ;->  When I was a cyclist, I
don't think I ever did the same ride twice in one week, except when I
was commuting to work.

> and I
> maintain the same average pace within 4/10 of a mph over the
> distance. My
> heart rate varies significantly, 10 to 15 BPM, with the same speed
> and
> conditions depending on what part of the workout and other parameters
> I'm
> not aware of.

Health and fatigue certainly will cause day-to-day variation, but I'll
bet that wind and subtle variations in terrain are the big factors
here.  

If you maintain 20 mph, just the difference between a 2 mph headwind
and 2 mph tailwind should be enough to explain your variation, but it
wouldn't be obvious without the speedometer.   At a kayak's speed aero
drag in light wind is very little of the total drag, so I would expect
wind to be less confounding.

At a racing pace, I was surprised to find how strongly I felt changes
in the slope of the road that were too small to see readily, often
requiring a gear change for an almost-invisible "hill".  At a less
desperate level of effort, you have more reserve aerobic capacity, and
can increase your output a bit without changing gears, often without
noticing unless you have a heart monitor or are really paying attention
to you effort.  Is there a marine analog to this?  Boat wakes come to
mind.  Anyone know if 8 inch/ 20 cm wavelets are significant?

If you were to do a couple of back to back runs in dead air and flat
water, I'm pretty sure you could see a difference, IF you can maintain
a truly constant speed.  I've never used a knotmeter, so I don't know
how hard that is.  

Lacking a knotmeter, if I were to try this, I would get warmed up
(paddle at least half an hour) then start well back from the measured
distance course and try to maintain a stable, moderate heart rate, say
140 bpm, and time a half-mile run, then repeat in the opposite
direction, then switch boats.  Better yet, bring someone to paddle the
other boat along, and do them in order a-b-b-a, hopefully minimizing
effects of changing conditions.

As Nick pointed out, the big advantage of a live-paddled test is that
it might reveal the differences due to ergonomics, which towed tests
would not detect.  Steering or "tracking" qualities would also be a
factor.  Subjective ergonomics are also an important area best seen by
back to back trials.

Mike Wagenbach
Seattle




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