help building a Shearwater 16' hybrid

[heneksja]

I am new to CPA and live in Laurel. I am going to purchase a kit from clc for a 16' shearwater hybrid. I have never build a kayak before. I do have some woodworking experience, but none with epoxy and fiberglass. I have a friend who also has no kayak building experience. It would be nice if I had someone who has done this to help out and offer advice during building.

Would there be anyone that lives around Laurel that would be interested. I am not quite ready to start yet, as I plan to get a new shed in my back yard, so I could move some of the stuff out of the garage, to have room to build in the garage. But before getting the shed, I got the prepare the site. Obviously, I can't build the foundation with 2+ feet of snow on the ground.

So I am planning to start the building project in mid-march. Anyone interested in helping out or advising?

/Jeff Heneks

[Ricky D.]

My father and I built a shearwater 17 Hybrid last year. We live around Annapolis and would be glad to help you out. There is also the CLC form on line you can learn a lot from checking out what others have asked and answered. If you like give us a call before you start. one other though, is there any reason why your going with the 16' boat. I'm a 5'3 150lbs and have no issues with the 17' boat.

Ricky D
443-829-8925 cell

[heneksja]

I tried out the 17 foot. It was fine. I guess I was looking at the other way around. Why would I want the 17 if the 16 would work. It seems like the 16 is going to be easier to fit on the car and in the garage. According to the specs on the clc site, the upper limit of weight is 190 lbs for the 16 foot. I am actually a little over that. I have been trying to loose weight (I'm 5'6") so I was looking at the 16 foot as a motivation factor.

So why did you go with the 17 instead of the 16?

By the way, I ordered my shed, but I didn't get it yet. It is ready, as soon as I get the site prepared, and melt the big pile of snow that is blocking the path that the "mule" has to get through with the shed.

[Rich Stevens]

The 17' boat will be faster and more efficient to paddle than a 16' boat. It will make it easier to keep up with a group and carry more gear. The majority of the people in CPA have 17 or 18' boats.

[puzzlepax]

A lot depends on your intended cruising speed as to whether a longer boat actually makes sense and is 'faster'. I came across the following well reasoned article in a new SOF website that makes some valid points...

http://www.kudzucraft.com/articles/longboatmyth.php

A longer boat may have other advantages for camping, if that's your thing.

Stephen
(paddling long skinny boats fast- my thing)

[gasserra]

Rich--

You commented above that a 17 foot boat will be faster than a 16 foot boat.

I think this is only partially correct. There are at least two other considerations.

First, the speed correlates with waterline length, not overall length. An Epic 18 with near plumb bow and stern should be faster than an 18' Nordkapp with raked bow and stern, and therefore a significantly shorter waterline length. With this principle in mind, it's easy to imagine a 17' racing kayak that was ultimately faster than the Nordkapp.

Second, the effect of the longer waterline has more to do with the upper limit of achievable speed, not with the hull efficiency at lower speeds. For this reason, for the same energy expended, a boat with a shorter waterline length could be faster at some range of speed within the envelope of its achievable speed. The paddler, perceiving the effort he/she was expending, would observe the shorter but more efficient boat to be faster. Of course, as the speed increases, that boat will eventually not be able to achieve the max speed of its longer rival.

Bob

[jesSea]

I don't know why we're always pushing people towards longer boats. Not everyone has the paddling skills to handle a 17-18 footer. Not everyone is a camper who needs the storage space for gear. Not everyone puts a top priority on going as fast as possible on open water. Not everyone wants to wrestle with loading and unloading the larger boat.

I myself have a 16' Romany and a 17' Shearwater. They're like night and day from each other, and each has its advantages. I certainly wouldn't consider the Shearwater better just because of its greater length.

I would also be curious to see the basis for the statement that "[t]he majority of the people in CPA have 17 or 18' boats." Admittedly my impressions are not based on careful counting, but I believe I've seen far more 16 footers than 18 footers around the club over the years.

There are situations in life where longer is better, however in the case of kayaking I believe it's more what you do with it.

J

[mattblakey]

In this discussion on length, are we still talking about kayaks?

[heneksja]

Humm, Matt I was sorta thinking that was what this was about too

I have not yet bought the kit yet. So this is a great discussion. For me the gear storage increase is not a factor. Maybe it would be if I ever wanted to camp with it. A 16 or 17 is so much longer than the 11 foot rec kayaks I have now (dagger blackwater and old town loon) The way I calculated my speed on the old town, I am regularly above the hull speed of it. It doesn't seem to be very limiting. I guess things may be different in a bigger kayak.

I have very little experience on open water. But I am interested in doing it more. But camping is not something I am thinking about. Maybe I would, once I got a kayak I could do it in.

Does that one extra foot in length really make that much difference anyway? Hull speed, seems to be about .2 mph difference. That doesn't seem like much. A couple of extra cubic foot storage space doesn't seem like a lot. But that extra foot storing in my garage is going to make a big difference, not to mention having space in the garage to build it. Even 16 foot is going to be tight.

[Rich Stevens]

Since we are talking about the same boat, an extra foot does translate to an extra foot of waterline.

I'll have to admit that I've always liked to do distance paddling, and if you're going to do 30-40 miles in a day, you've got to maintain some speed and a few tenths of a mile per hour add up over the course of a day. I like that idea that I can explore many areas of the bay in a day trip that are accessible to others due to the distance and lack of local access. At the same time, at 5' 6" I've never found an 18' boat to be a burden on or off the water, although it is Kevlar.

My perception of most people having 17-18' boats is probably colored by the people that I tend to paddle with.

The only reason I tend to suggest a longer boat, besides my own preferences, is that a fair number of people tend to get shorter boats to start out in, and then buy longer boats in a year or two. It's pretty rare that a person gets a shorter boat, unless it's a second boat for a particular purpose.

Ultimately, it's up to the individual to decide what they intend to use their kayak for, along with considering things like cost, storage, loading, transporting, etc., that should determine what boat to buy. Not everyone is into speed and/or distance, or camping. There are a number of things that a longer boat is not good at.

[Nutfarmer]

Thanks for the link puzzlepax! nice discourse on efficiency, length and horsepower. Got to look at many factors when deciding on a boat for a purpose. As in flying, horsepower makes up for a lot of other sins, put in a bigger motor, ie some conditioning and keeping pace won't be any problem.

My experience is that most trips are not paddled at 'maximum true' hull speed for hours on end.

[Mihail]

The 17' is 22" wide, the 14 and 16 are 23" per CLC. That means the 17' will have potentially better top end speed. And by top end I mean it will be easier to paddle above 4-4.5 miles per hour or so.

Being narrower by an inch than the 16', the 17' *may* actually have similar drag at low speeds compared to the 16'.

Many people make a valid point that the longer boats are harder to paddle slowly (2-4 miles perhour) than shorter ones due to more wetted surface (all else being equal). While this is factually correct, the differences are quite small. But once the boat reaches speeds of about 4+ miles per hour, a shorter boat begins to hit much higher resistance quicker.

Compare for yourself: http://unold.dk/paddling/articles/kayakvelocity.html

A 13.6 foot Perception Sonoma (actual waterline length more like 12.5 feet) vs. a 16.9 Necky Looksha IV (probably 15.5 waterline length). That's a typical 14 vs. 17' boat comparison (same width, same volume). Up to 3.5 knots (4 mph) they are neck to neck with the differences in effort needed to maintain that speed so negligible that it does not matter. Above 5 mph - the Looksha (itself not a speed daemon) begins to get easier to paddle compared to the Sonoma (but both are a *lot* harder to paddle faster than slower).

The Looksha requires 0.86 kg of pull (just under 2 lb) to move at 3.5 miles per hour (3 knots), the Sonoma requires 0.85. The difference is 0.01kg, which is 1/3 of an ounce - my watch weights 10 times more!. Absolutely negligible difference to propel a 14 footer vs. 17 footer here!

Look at 4 knots (4.6 mph). Note that this speed is typically considered too fast for the average trip CPA makes. The 14 footer here requires 1.74 kg of effort (twice as much as at 3 knots) and the 17 footer needs 1.63kg. The difference has now grown to a "wooping" 0.11kg, which is less than about 3.5 ounces (as much as the average watch weights). How much is that? Not much at all, IMO.

The almost 19 foot CD Extreme (17+ foot waterline) in comparison requires 0.88 vs. 1.59 for 3 and 4 knots respectively. That is onl a 1 once difference at 3 knots compared to the Sonoma. Nothing. At 4 knots the difference begins to be felt at but is still quite small at about 0.15 kg (4-5 oz). Keep in mind the Extreme scored "best" overall at the 4-5 knot mark as compared to about a 100 other kayaks so it is a tough act to beat at that speeds but is somewhat more tippy than the Sonoma and the Looksha IV).

The above shows that 14 vs. 17 foot makes virtually no difference for speeds up to about 4.5 mph. Even most 18 and 19 footers will offer no advantage to the average paddler who is rarely going to exceed 4.5 mph for extended periods of time.

Are you going to go faster than 5 mph for extended periods of time? If yes, then you would be indeed better off choosing a longer boat (and narrower too).

Paddling a 17-18 footer at 5 mph for an hour takes considerably less effort but paddling a 14 footer vs. an 18 footer at 4 mph makes no difference whatsoever.

In my 18 foot Rapier I can definitely cover more miles in a 2-3 hours chunk of paddling time than in my Sonoma but the difference for me is not that big actually even when pushing my own "speed linits". In the Sonoma my average speed over a 15 mile paddle has been consistently in the 4.5 mph range (and that includes short on-water breaks, I'm actually paddling it at just under 5 mph most of the time). In the Rapier in similar conditions I am a little above 5 mph, may be 5.3-5.5 or so. If I race it, I can do a little better, but have yet to hit a 6 mph average over anything more than an hour long.

When I have gone out with CPA trips, I have hardly ever paddled at more than 3.5 to 4 mph average so to me a longer than 16 foot boat is really not needed "to keep up" on most trips.

A shorter boat is actually a lot of fun in the choppy Potomac and Chesapeake waters in short-period wind waves and it may actually be faster than a longer boat! A longer boat smooths-out the ripples (e.g. does not benefit from surfing up or down wind". It stays level in very short small waves and just cuts through the water and moving all that water to the side takes quite a bit of energy even though the ride is smooth. If driven against sort period steep the longer boat dives into the wave, jumps up over the crest, then slaps down and loses a lot of energy doing so. In comparison, a shorter boat slides up-over then surfs-down the waves without having to cut and displace water that much more than it would when paddled in flat conditions. In waves with my short boat I maintain almost the same speed as in flat water if going up-wind and go about as fast as the waves go or a little faster if going diagonally downwind. And with some practice you can actually surf upwind, on the back of the waves -;). In that scenario the longer just does not fit b/w two wave crests as a short one does.

But when the wave period gets longer than 2-4 seconds, the longer boat begins to settle down and has an advantage over a shorter boat - now the longer boat can do the tricks that the shor boat did in the short period waves. It can now surf fast where the short boat often falls off the waves since it can't maintain a high top speed.

So, where a ong boat may be better in some conditions, a short one will be better in others. Got to figure out what kind of paddling you will be doing most of the time and decide on the best boat for that.

I've been happilly paddling my 13.5 foot Perception Sonoma for more than a year now and I never felt I needed a longer boat to keep-up with others on short day trips. Only when racing above 5mph it falls, well ..., short . It is however unquestionably easier to live with - light, easy to maneuver on and off the water, and allows me to go into some white water too, where a 17-18 footer would fare considerably worse.

As for the weight range, I am not sure what to say. For mainly day trips, I'd go with the "one size smaller" approach. I'm 185lb before gear and about 210lb with light winter gear (only what I need on the water for a few hours, no camping etc.). So, at over 200lb in the 13.5 by 22"-22.5" wide Sonoma I feel it handles the weight just fine. I can't imagine why a 14 or 16 Shearwater would not be at least as capable in terms of weight capacity.

[kver]

I second Mihail's comments - length isn't everything - even with the similar hull design, a shorter boat which sinks faster may have a longer waterline than the longer boat at a given weight - as a lighter paddler when I'm in a longer boat i often have most of the boat out of the water anyways...

The 16 will work better in back creeks and surfing Chesapeake chop the 17 is MUCH better for camping and more rewarding for steeper waves and leaned carvy turns...

you could always build 16 x 22 and get the best of both worlds -- lose a tiny bit of stability and carrying capacity in return for decreased wetted surface area, (less drag) higher top end, more maneuverability and better manners in waves and rough water ---- The 16x22 was tested as a prototype and got rave reviews but was rejected because it was a little tippier than a neophyte kayaker would feel comfortable in - but unless you're talking about a racing boat or surfski as opposed to a genuine sea kayak --3 hours in a tippy boat and it feels like home... BTW CLC might still have one hanging in showroom.

[Rich Stevens]

Of course when you multiply that three and a half ounces by about 8,000 paddle strokes for a ten mile paddle...

[Mihail]

You got a very good point and I agree that ounces do add-up.

However, let's just note that the number of strokes has nothing to do with it. It's not like multiplying 8,000 strokes times 3.5 oz - that math would simply be wrong. What matters is the energy expended to overcome the resistance and that does not directly translate to number of strokes (just think of it - one can do faster cadence at lower effort per stroke or slower cadence with a larger paddle and more effort per stroke). So we can't just take the 3.5 oz and multiply by a number of strokes.

Instead, we need to look at the work (or energy) needed to overcome the resistance over a certain distance. This is measured as the force times the distance. It is measured in foot per pound (e.g. 1foot-pound energy is the amount of energy needed to lift 1 pound to a height of 1 foot relative to where it was before). We can use that formula here too: Energy = Miles * Weight and can be measured in ft-lb units.

The total energy expended to move the kayak for 10 miles is thus equal to the pull times the distance (keeping in mind the pull or "weight" is not the weight of the boat but the resistance it sees in the water as measured in lb).

Let's first look at a speed of 3 knots. The effort needed to move the 14 footer at this speed is listed as 0.85kg = 1.874lb. The 17 footer requires 1.896lb for the same speed. That means the 14 footer needs 0.022lb less pull to move at 3knots (3.5 mph).

Let's see what the *difference* in effort (e.g. energy spent) would be for 3 knots:

Energy = Distance * Weight = 10miles * 0.022lb = 10miles * 5,280feet-in-a-mile * 0.022lb = 1,162ft-lb.

EDIT (my math was off in the basic conversion of the above to how many times I need to lift the kayak over the car roof). Fixing that here. That's about as much energy as it is needed for lifting about 3 times times from the ground to the roof of a vehicle 7 feet tall a kayak that weighs 60lb! I'd say, that's a a notable savings over one trip if one goes at 3.6 mph but not huge.

So, in the case one is moving slowly, I proved myself wrong only slightly, I guess. The shorter boat at 14 feet is only a little easier on the body compared to a 17 footer!

I'm willing to bet, however, that at about 4 miles per hour it will likely be toss-up if a 16 vs. 17 foot boat will move easier.

Now I'm getting scared that I will prove myself wrong again. Let's now look at the difference b/w 14 footer and 17 footer at 4 knots or 4.6 miles per hour for 10 miles. Applying the same math as above:

(1) the difference in the pull is 1.74kg minus 1.63kg = 0.11kg = 0.2425lb approximately.

(2) Energy = Distance * Weight = 10miles * 0.2425lb = 10miles * 5,280feet-in-a-mile * 0.2425lb = 12,804ft-lb

That's 11 times more energy that the 14 footer wastes at 4 knots compared to what it gained at 3 knots relative to the 17 footer!!!

So, a 17 footer will be easier to paddle at 4 knots than a 14 footer. Exactly how much easier? As much as to lift a 60lb kayak 30 times from the ground to the roof of the car 7 feet above.

This means that I am a little more incorrect, in saying that the difference in effort was "only" 3.5 or so oz

Are we wasting that much energy paddling 10 miles???? Save the planet - don't paddle Or if you have to paddle, paddle slowly in a short boat OR fast in a long boat!

If one has the #s for the 16 vs. the 17 footer Shearwater, one could I guess do the math and decide for themselves ...