Upwind is a Heavy or Light boat best?

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9 years 9 months ago #15451 by Kneewall49
Thought I thought I'd bait a line with this one.

Two boats identical except for layup, lets say a V10 Sport double; one carbon layup and the other a vacuum glass layup.

Same paddlers in both, same conditions, ie smashing into a short head wind 1-2 foot chop (in protected waters, ie no swell).

Is one boat going to be faster, or easier, to hold at a set speed than the other?

Scientific evidence preferred over assumptions or opinions. :)

(no comments from you BD!)

Northern Beaches, Australia.
[Fenn Swordfish, Fenn Spark, Carbonology Zest Double
Pain is temporary, glory can be even less so...

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9 years 9 months ago #15452 by sAsLEX
There will also be a measure of flexibility in the different lay ups that will affect the result.

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9 years 9 months ago #15453 by Kneewall49
sAsLEX, from your comment I'm reading that flexibility is a detractor from speed than flexibility is?

If so that would be less of an issue with lighter paddlers than heavy ones?

We are both around 70kg each. Small fry.

Northern Beaches, Australia.
[Fenn Swordfish, Fenn Spark, Carbonology Zest Double
Pain is temporary, glory can be even less so...

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9 years 9 months ago #15472 by owenw
Simple physics (and discovered by a Mr Archimedes a long time ago); if EVERYTHING else is equal, the lighter boat will always be quicker (no matter what direction) as you simply have to move less water out of the way with every paddle stroke (1 litre per Kg).

Life truly lived is full of risk; to fence out risk is to fence out life itself

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9 years 9 months ago #15474 by [email protected]

if EVERYTHING else is equal


Part of what I love about surfski paddling is that the complexities of of ski design and conditions mean that there's a large measure of magic that comes into play along with science.

For example... some people feel that stiffer skis are better; flexible skis "leak energy" as they bend over the waves.

Sounds like sense to me. But a couple of years ago we had the opportunity to try two different versions of the Red7 Surf70 Pro: a "heavy" but stiff carbon boat and a "light", flexible cork composite boat. They were identical in everything - including weight - except for the flexibility. We took them out into choppy water in Hout Bay and we both found that (as mid-packer paddlers) we were faster in the cork boat. The reason was nothing to do with the flexibility but rather that we both found the stiff carbon boat much more tippy. We theorised that the cork boat's flexibility meant that the centre section sat lower in the water and it was hence more stable.

Similarly, in my opinion, a heavy boat can be easier to paddle upwind, because it doesn't get thrown around as much by the wind - especially if there are waves and you're ramping them, exposing the ski's nose to the gusts. Paddling out to the start of our Millers Run downwind route, we paddle diagonally into the wind and it can be quite hairy as the nose of the ski gets flung sideways as you go over the waves.

And there are more factors in play. For example, the slab sides of the Fenn Elite and V10 are more prone to being blown sideways than the slimmer noses of, say, the Swordfish or Think Evo II.

Rob

Currently Fenn Swordfish S, Epic V10 Double.
Previously: Think Evo II, Carbonology Zest, Fenn Swordfish, Epic V10, Fenn Elite, Red7 Surf70 Pro, Epic V10 Sport, Genius Blu, Kayak Centre Zeplin, Fenn Mako6, Custom Kayaks ICON, Brian's Kayaks Molokai, Brian's Kayaks Wedge and several others...

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9 years 9 months ago #15478 by Love2ski
Great question. I think the model of boat is very relevant. I have very light and stiff carbon fenn xt. I am also beginner moving towards intermediate.

The boat is very buoyant, visibly so against glass boats. It moves all over the place upwind, but flys downwind. In our regular racing I am often bumping around uphill but pass loads of guys downhill.

In some ways it feels like it sits on the water not in it.

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9 years 9 months ago #15479 by AndyN
Replied by AndyN on topic Re: Upwind is a Heavy or Light boat best?
I have a very light V12 and the use of a glass V10, not a direct comparison I know but whilst the V12 is definitely quicker in almost all conditions the heavier V10 with lower volume front end always feels more efficient into wind and waves and my Garmin readings seem to confirm this.

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9 years 9 months ago - 9 years 9 months ago #15480 by sAsLEX

owenw wrote: Simple physics (and discovered by a Mr Archimedes a long time ago); if EVERYTHING else is equal, the lighter boat will always be quicker (no matter what direction) as you simply have to move less water out of the way with every paddle stroke (1 litre per Kg).


So why is an air craft carrier made long instead of light?

EDIT misread your post, so yes a lighter boat would be faster in flat water no wind.

If the lighter boat sits further out of the water if has a greater surface area to the wind, acting more like a sail.

The heavier boat may also punch through waves and not slap and stop as much.
Last edit: 9 years 9 months ago by sAsLEX.

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9 years 9 months ago - 9 years 9 months ago #15481 by Kneewall49
Thanks for the discussion, great so far.

I often think about 'momentum' vs acceleration'. I know a very heavy boat will take longer to accelerate than a very light ship, but on the other hand a very heavy ship will glide a long way to stop in comparison.

So, yes you'll spend more energy getting up to speed, then what? In a straight line race like this weekends (great) Bridge to Beach, we'll be steaming off the line and redlining it the 11 ks to manly.

So will we use left effort overall once up to cruise speed? Despite my request for no assumptions/options, I think we probably would, as well as not getting so knocked back by frontal chop.

Northern Beaches, Australia.
[Fenn Swordfish, Fenn Spark, Carbonology Zest Double
Pain is temporary, glory can be even less so...
Last edit: 9 years 9 months ago by Kneewall49.

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9 years 9 months ago #15482 by Marieski
We have several issues, 4 already mentioned:

A lighter boat displaces less water: less drag:faster.

A lighter boat, faster to accelerate but less momentum. Under flat water circumstances or in a world where wind and waves not interrupting direction, stability or paddling rhythm lighter is still better.

Stiffer boat is tippier, because it transmits rather than absorbs every perturbation and/or because it bends in the middle making the weighty bit lower in the water.

Heavier boat gets blown around less, especially when direction is not directly upwind, meaning you are traveling a straighter line and your paddle stroke will be more efficient.

I'm afraid the answer to your question is very much dependent on conditions: if going directly upwind in a regular sea, I'd say the light boat. If messy and/or partially sideon, the heavy.

The list of observations is too long, but these conclusions came from testing my plastic Spirit PRS vs Performance V10Sport vs Elite V10L in different conditions with Garmin and more recently the Custom Horizon vs Flow Superstar vs Swordfish vacuum vs Stellar SES advantage. I realise there are more variables than weight!

Past skis: Spirit PRS, EpicV10Sport Performance, Epic V10 Elite, Stellar SES Advantage. Current skis: Fenn Elite Spark, Fenn Swordfish vacuum. Custom Horizon, Epic V7

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9 years 9 months ago #15485 by Dicko
The simplest answer is " if a heavy boat is faster, then the elite paddlers would all be paddling 17 kg boats". To my knowledge they all paddle boats weighing between 8-11kgs. Must be a reason for that.

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9 years 9 months ago - 9 years 9 months ago #15490 by Physio

Dicko wrote: The simplest answer is " if a heavy boat is faster, then the elite paddlers would all be paddling 17 kg boats". To my knowledge they all paddle boats weighing between 8-11kgs. Must be a reason for that.

i don't think this answers the question, there are not many purely upwind races
from my limited personal xp one of my training partners is in a very light boat sub 10 kg and mine is 12 upwind she gets blown around and i pull away as soon as we turn downwind she catches runs early and starts to pull away, not at all scientific and not the same ski same length but hers 20mm narrower
even when the wind is directly head on her nose goes much higher and slaps down harder, again different ski nose shape could do this.
ps i dont think you will get a technical answer there is way too many variables
Last edit: 9 years 9 months ago by Physio. Reason: addition

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9 years 9 months ago #15493 by kayakchampeen
Sorry Dicko but that's a gross oversimplification. Seems like you often answer similar questions with (paraphrase) "well if it's not what the pros are doing it must not be valid". The question pertained directly to upwind legs. We all know that downwind races put a premium on a lighter boat for acceleration in order to catch runs, and this obviously the reasoning behind the top dogs choice of (discounted and disposable) craft. Pros generally can't stand racing into the wind, and get their panties all in a bunch when conditions conspire to make the race a grind. Their choice of skis has ZERO to do with what works best upwind. It may well be that a heavier boat would work better at other points of sail than downwind. I don't know the answer to that question. But I do know that the top guys choice of craft has nothing to do with this. I can also tell you that just b/c someone is world class in the ski doesn't mean that they have a more thoroughgoing knowledge re. hullforms, boat design, composites, paddles or any other aspect of ski paddling. One could be a total naif at all that and still dominate if you had the skill, strength, stamina, and guts to win. I have seen many world class competitors in various sports that did little else but copy what "everyone else was doing" without the slightest inkling as to the wherefores and whatnots. One doesn't have to be Oscar to intuit what works best. If everyone had an attitude similar to yours we would all still be paddling Kleppers with 240cm paddles. Innovation comes from those who don't assume a priori anything having to do with the finer points of their respective fields of endeavor.

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9 years 9 months ago #15494 by Dicko
I have found the opposite. I have a mate who has the same boat as me.
He has a 11.5 kg hybrid. Very stiff and light. My boat is 15.5 kg glass with extra glass. Also very stiff. Downwind we are almost the same. I may have a a few metres on him over 5km. Upwind he pulls away.

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9 years 9 months ago #15495 by owenw
As per the original question assuming everything else was equal, unequivocally science proves lighter is quicker.
Anecdotally: my wife and I each own a Stellar SR; hers in Excel layup (Nomex/Kevlar) and weighs 11.5Kg, mine in Advantage layup (Soric/Glass) and weighs 15Kg. I paddle both (when she lets me) and hers is clearly quicker upwind, downwind, crosswind, long distance, short distance et al!
Ben Lexen (the great racing yacht designer) once observed that extra weight is only an advantage in a steam roller.

Life truly lived is full of risk; to fence out risk is to fence out life itself

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9 years 9 months ago #15496 by PaddleFaster
Being that the difference in speed wouldn't be anymore than about 1 or 2 tenths of a kph, that aspect of the equation really doesn't matter much to me. Besides, no one is watching me when I do it so I can always fib a little bit and say I was five minutes faster.

Besides, if my paddles takes 5 minutes longer over the course of three to four hours paddling, that just means I get to spend 5 minutes more out on the water and as far as I am concerned.

But that's not the question that was asked.

To answer it, I need to use my intelligence to formulate an opinion based on experience, facts and all of the knowledge I have accumulated in half a century on this earth...

So my answer to the question put forth in the debate is as follows...

I have no idea whatsoever!

Could someone pass over the chips...

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9 years 9 months ago #15497 by Dicko
Kayakchampeen..."what". Just an opinion. Have no idea what I'm talking about. But, why then in a K1 race is the minimum weight of a boat governed. You would expect that if these guys were paddling into the wind and a heavier boat was faster, before the race they would be weighing their boats down with anything they could find, wet towels, sand etc.
Now that we know most ski paddlers are stupid, does this also apply to the half dozen coaches and sports scientists that hang out with every top athlete. We have to assume they know something about what's quick.

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9 years 9 months ago #15498 by Kneewall49
Boys, all good info and views. Please remember, I'm only asking this question in relation to upwind, and short chop, with light weight and B grade paddlers.

There are many advantages of a light boat, and one disadvantage that I can vouch for personally. At 70kg I was slower to windward in a lighter boat (open ocean) simply because the lighter weight made the craft corky, and I could not apply all strokes as power ones.

Thanks. Keep the comments cool.

Northern Beaches, Australia.
[Fenn Swordfish, Fenn Spark, Carbonology Zest Double
Pain is temporary, glory can be even less so...

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9 years 9 months ago #15500 by Dicko
The way I look at it is, if I had an 11kg boat and filled the cockpit with 4 litres of water would it be faster...I don't think so.
The question comes back to stability. And that's a whole new thread.
I found when I paddled tippier boats that paddling into the wind was when I felt most stable. Having said that I've always had heavier boats anyway. If I could afford a light boat I would probably get one, cos it seems that whenever one of the guys I paddle with gets a lighter boat they go quicker into the chop and on the flat....and we are all well past middle age and all aspire to be B grade.

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9 years 9 months ago #15502 by Metro
A well trained paddler can generate perhaps 1.5-2.0 horsepower peak, let's say .3-.4 horsepower sustainted (obviously more for Olympians, etc). That is not much power. We are not going to be flexing hulls, ripping out bulkheads, causing paint to fly off, etc. With that backdrop, the starting principle has to be that lighter is faster. If you don't have much power, you want a light rig. Now, if you have a surefit of power (think V8 engines), you may need weight to keep from destroying what the power is being applied to (with the result being that heavier may be faster in that instance). But, again, the excess power scenario is not applicbale to the sport that we all love.

Now let's look at upwind paddling in particular. We start with low power and then add in natural resistance. A good comparison is riding a bicyle into the wind, or riding a bicyle uphill. Not only is weight harmful in those instances, having a light machine is actually more critical than when paddling / riding downwind or riding downhill. Think about it: Flat time trial, you grab your bike relatively unconcerned about the unnecessary spare tube strapped under the seat. Uphill time trial, you dust the thing after removing the front derailleur. Same principle with skis.

The distinction that some folks seem to be making in this thread is that they get blown around in a headwind, get the wobbles and so can't apply full power. Sure, we can stipulate that. No different than a "fat" boat will be faster for a new paddler than will be an elite boat. BUT, if the question is: What will be faster for a paddler (or pair of paddlers in the case of a double) of solid ability who has the experience to paddle in all conditions: Lighter is faster than heavier (just as narrower is faster than wider).

Also, in the case of doubles, remember that the captain gets to pick the boat and no discussion, let alone dissention, will be tolerated.

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