Cruising speed?

Am in a few - sort of
The clubs here (FT L - Miami) are on the small side and largely run by email.



The one I am semi-active in has some great people - mostly of a greenland paddle/brit boat bent - with a couple other QCC GP’ers. So far good for leisurely paddles and the occasional rescue practice. The other groups seem more focused on Rec/SOT/inland river trips/fishing/etc.



Surf Ski community exists too, but is small and scattered compared to West Coast. It will be quite some time until I consider myself part of it. Owning one is not that same as being able to paddle one in the ocean, and I have not had the time/motivaton to really do more than play a few times so far. Can just about stay on it in flat water, but not long as the balance muscles for knees up paddling are still taking a beating. I am still slower than on my Q700 as I’m working hard to just do it at all.



Florida Competiton Paddlers Assoc. is another resource - but as I said - I’m not pushing the race aspect right now. May jump in the next season and do some just to do them. I’m picky though, and want water deep enough to paddle in. Portaging is for canoes!

NEAT BOAT!

Portaging?

– Last Updated: Jul-01-04 3:02 PM EST –

Kris,, even though there have been a few FCPA races where the water has been shallow in areas, portaging is rare,, in fact, only portaged in one race for about 10 yards to get over a sand bar. Paddling in the shallows is a bear though,, great workout!

HEX

hull speed
When paddling alone and in the mood for a pleasant but nice energizing time I am generally in the “high 3 to 4” range, but the thing I try to be aware of is how the hull is performing. When I am nearing that point when either realistic max. hull efficiency or hull speed has been achieved, I realize that beyond that the effort for the speed gained isn’t worth it unless it is for a specific reason.



My boat is similar to the Romany, and once she goes just beyond hull speed, she squats a little in the stern.



Try to work within the limitations of the boat for max efficiency.

Shallows
You can use the aded drag in the Q700 as a depth guage! I really feel the bottom in that boat, even if its 6 ft away. Gets all boats - EFT any better?



I’d heard there was portaging in some FCPA races - and slow narrow rivers on others. Generally PIA stuff that not only slows but can beat up your gear. If that’s not the case - great.



Ski would be awesome for portaging (on fairly level ground in low wind at least!).

Narrow rivers, absolutely!
Slow, sometimes. Not the best course for a ski though. some of the rivers have tight turns, too tight for a 21’ski. Ruddered boats are a necessity in some of the rivers. A couple of the races are in protected bays, great for kayaks, too flat for skis. The starts can be rather bumpy with 30 or more boats in a 20 to 30 foot wide river jockeying for position, very different than the B&B start.



HEX

"symptom of speed, not an obstacle"
Posted - just because it bears repeating, as it dispells many misconceptions regarding hull speed, bow waves, stern squat, etc.:



Speaking Good Boat, Part II (Hull Speed and Beyond) - by John Winters



“Hull Speed”, like prismatic coefficient, is a much loved phrase by

pundits and paddling “experts”. “This boat has a high hull speed.”

(few ever have a “low” hull speed) or “We were paddling at hull

speed.” are commonly used to imply that “hull speed” is a limit to

displacement speeds and bloody fast at that. The more daring suggest

that planning lies just the other side of the magic number. You know

better, or will when you finish reading this.



The great pioneer of hydrodynamics, William Froude, coined the phrase

“hull speed” when he discovered that extraordinary amounts of power

were needed to propel the ships he was testing any faster than in

knots. It was, for him, a practical but not an absolute limit. The

speed corresponds to the speed of a wave having the same length as

the effective waterline length of the hull. To see why the resistance

grew so rapidly we must first know that there are two major types of

waves formed by a boat - transverse and diagonal. We can ignore the

diagonal waves that have only minor impact on resistance and

concentrate on the transverse system. Figure 1 shows the wave systems

as viewed from above. At this point things get a bit more complicated

because a transverse waves are created at the bow and at the stern.

As boat speed increases so do the wave lengths created and at some

point the length of the bow wave will match the length of the boat

and its crest will coincide with the first crest of the stern wave.

When two waves coincide in this manner their heights are additive as

shown in Figure 2 and resistance increases accordingly. Since wave

size is a function of displacement, heavy boats make big waves and

light boats make small ones. Additionally, the longer the boat, the

faster it can go before the two waves coincide. Hence the common

wisdom that long boats are “faster” than short boats which is

perfectly true to a point. The “point” is that small light boats make

such small waves that they are easily driven beyond “hull speed” and

long light boats have higher wetted surface that offsets the

reduction in wave making resistance.



You will recall that the bow wave lengthens with increased speed.

Suppose you have enough power to get the bow wave crest aft of the

stern. If you can, an interesting thing happens. The trough of the

bow wave coincides with the crest of the stern wave and begins to

cancel it out as in Figure 3. The result is reduced wave making

resistance. Once past “hull speed” wave making resistance increases

very slowly and, can even drop while frictional resistance continues

to increase. Since a shorter boat has less wetted surface than longer

version it is apparent that there are times when a shorter boat is

faster.



An interesting phenomenon is the change in trim as speed increases.

As the trough of the bow wave moves aft, the stern sinks into the

hole and the bow rises. Some writers have said that it is this “hill”

of water that the boat must climb and attribute the “hill” to the

increased resistance. A little common sense will clear this up. How

do you climb a wave that is being constantly created by the bow? As

fast as you climb it a new one is being created in front of you. One

can just as easily lift oneself by his own boot straps. Some eighty

years ago Admiral Taylor the great naval architect explained that the

change of trim, was a symptom of speed, not an obstacle. few kayak

designers have read Taylor’s classic text book on naval architecture,

“Speed and Power of Ships” and can be forgiven for not knowing this

important fact.



So what happens if the boat does start to level off? Isn’t that

planing? Regrettably, not always. For a boat to plane its center of

gravity must lift bodily from the effect of dynamic forces on the

bottom. It takes an enormous amount of power to do this (Imagine

lifting a weight equal to yourself and the boat and then imagine how

difficult it is to do it by paddling!). No one has yet demonstrated

planing in a canoe or kayak despite the claims. Any reduction in

resistance at high speeds is due to wave cancellation and not wave

size reduction due to the reduced displacement that accompanies

planing.



So, why did Froude screw things up with his “hull Speed” business?

Well, he didn’t. At least not for people who read the fine print.

What Froude said was that wavemaking resistance increased rapidly as

hull speed was approached. He did not say that hull speed was the

limit to displacement speeds. He just didn’t have the power or light

construction we have today to make it an issue (nor was he much

concerned about the resistance of native kayaks) Today modern ships,

kayaks, and canoes are light enough or have enough power to easily

surpass hull speed. In fact, we regularly test sea kayaks at S/L 1.5

and sprint kayaks and canoes can top S/L 2.0.



So how should we use the term “hull speed” when speaking Boat? That’s

easy. We shouldn’t. And, when others do, just point out that “hull

speed” is a term of convenience referring to the speed at which the

bow wave length and boat length are the same and that it doesn’t have

any real significance for boats of low displacement length ratios

like kayaks. It should be enough to establish yourself as an expert

in nine out of ten kayaking conversations.



Copyright © 1996 by Redwing Designs. All rights reserved.


Enjoy the “rear” view
"I have no idea how fast I go, but I know I spend most of the trip looking at the back of Chuck or Pams heads…"



In the same boat, so to speak, I do that all the time, and it’s not just for kayaking!



I’m smaller both in lung capacity and muscle mass than average. I know people say you can “train”… But when you’re over 30, 40 or 50 year old, you’re not “training”. You’re just trying to “utilize” as much as possible of what you got! So, when I don’t get a whole lot to start with, there isn’t a whole lot I can do…



When I started cycling seriously (for me), I found myself looking at the back of most my of riding buddies. So I worked on it and got a lot better in efficiency and stamina. The result? I can hang with the old gang alright, but they want to quit when I’m barely warmed up. So I move up a notch and repeated the same process (looking at the back --> hanging happily). 3 years later, I have the stamina to complete a century (100 mile) but I’m too slow for the century folks. So I usually ride with groups that goes 50-70 miles, except I really would like to do more distance. One time we got lost and ended up with a 85 mile ride. Everyone was pissed and struggling. I thought that was one ride I REALLY, TRULY enjoy the most! :o) I’ve reached the point I don’t care to “improve” any more because I’m ALWAYS slower than people who want to do the same distance, whatever that distance maybe!!!



I’m still on my 1st/2nd season of sea kayaking so I’m the still the slowest on most trips. But I suspect I’ll probably ended up in the opposite of Greyyake and Santacruzmidwife: too slow for the distance people, but the slower people (i.e. who has similar speed as me) can’t/don’t want to go the distance I like to go. By the time I got better to hang with the group I used to lag behind, I may acquire the taste to go further… repeat after a season or so with a different group…

good question
i’ve been out 5-6 trips with my new GPS to check speed & distance, and had a few surprises. first, i’ve got 2 yaks, a scupperpro t/w that i’ve had for about 4 years. i look at it as a SUV, use it alot for fishing/camping around Tampa Bay, great boat for what i use it for. i did a 10K race 2 summers ago & had a time around 1hr23m, which i think comes out to around 4.2mph for “race” conditions. but, usually my pace is much slower as i “fart” around fishing the mangrove shoreline & oyster bars, speed is not important as most fishing trips take in 4-5 miles.



my new second yak is a QCC600. i bought this new ride with the purpose of having a workout/touring yak. my crusing speed (after getting warmed up) is 5.2-5.4mph (thats on the GPS). it doesn’t seem to change much from flat water to slight chop on the gulf waters off the beach. when there is much more than a chop on the gulf water i have a hard time of increasing my speed, guess that rolling throws off my paddle stroke some. on flat water inside the ICW i can do 6.0-6.2mph for 30 minutes or so if i keep my mind on it.



i have installed a Spirit Sail, that i had on my Scupperpro, on my QCC. Last weekend off the beach i had almost downwind conditions for the return (thankfully) leg of a 20 miler. good swell, with a 12-15mph wind at my back i had no problem with 6.0-6.3mph with a very relaxed paddle candance. if i push my stroke rate up a little i had 7.0mph on the GPS. My max speed (on GPS) for the day was 9.4 (whoowho!).

How accurate is GPS?
I was on my couch working with my GPS for about an hour. Did not move a bit. During that time my max speed was 3 mph, average 1 mph. It showed the distance I had traveled.



I think at slow speeds GPS may be less accurate than at high speeds for speed and distance.

GPS are very accurate
What you were probably experiencing is the difference in satelites that were being tracked. On my Garmin Legend I have a “satelite” screen and it graphically represents how many are being tracked and how accurate the data will be. Typically, I get about 17 feet in accuracy but it fluctuates without me moving. Think about it, the earth is revolving and so are the satelites up in the sky. If you move the GPS from one hand to the other it will record that as well even though you haven’t moved your feet. And perhaps that is how you recorded 3 MPH.



Take your GPS in your car and compare your speedometer to the GPS’s and you will be amazed at how accurate it is. YMMV.



Jeff

GPS is very accurate
My GPSMap76 is very accurate and very responsive. It will immediately show a drop in velocity if I have one weak stroke. Its great for refining stroke technique.



BTW I cruise all afternoon at right around 5.5 -6 mph. I can push QCC700 up to over 7.5 mph in flat water but its an effort to stay there. I have recorded a top speed of 12.5 mph while surfing waves. I always have a good idea of what the current is doing based on my GPS speed over ground and the effort I am putting in.



I do not use GPS every time out, but when I do I push a little harder to keep the numbers good. Its like having a coach onboard.

Same experience with same unit

yep pacing with the map 76
is relentless.

Ignore max speed on GPS
That number is not very accurate no matter what.

Sitting on your couch inside does not give you a good signal or clear view to satelites. If you test your GPS by jogging on a measured track you will see it does a good job for average speed at 4 or 5 mph. (Of course you may have a crappy model but I doubt it.)

why?
since i’ve only had my GPS for a few weeks & only very briefly read the owners manual maybe I am overlooking something, but why ignore the max speed reading? It seems to work well in my truck on the interstate, why would it not work as well with the single digits on a kayak?

Not sure I can exlplain it well
Not sure I understand it either but this is what I think is going on. The GPS is accurate to say 15 to 20 ft. When it erroneously measures your position has changed by say as much as 30ft (total error) in less than a second it gives you a higher instantaneous rate of speed. Averaged out over a few seconds these errors disappear. At higher speeds the error of 15 ft is insignificant so it will give better readings at high speed for top speed. I once got pitchpoled and thrown in big waves and my GPS read max speed of something like 27 mph. (Now I doubt that was a real reading too.)

I don’t ignore it on mine…
…and I think it is pretty accurate.

I’ll be doing some intervals and trying to hold it at a 6MPH pace, and somewhere in the middle, I will go all out.

When I check the max afterward, it will be a 7.0 or a 7.2, and to me that is pretty accurate.



cheers,

JackL

top speed
the top speed measurement is one of the easiest for an error to show up in but it is usually pretty obvious when it does.



We use them specifically for measuring top speed in RC Race boats. Checked against Stalker Radar they are usually dead on.



Again, it can show errors but it is usually pretty obvious.



db

i have the answer
for Seadart’s 27MPH max speed reading. maybe that WAS the speed of your unit as you were being pitch poled, kind of like the 'ol catapult/lever arm type of thing. i used to pitch poled my Hobie Cat during my teenage years on purpose just to feel the rush of free flight as I would get “launched” as the Hobid would bury into a wave and go from surfing at 20MPH to zero in about 2 seconds.