Effects of Boat's Design On Paddling

[beekeeper]

Criteria; flat bottom, pirogue or narrow beateau type boats, flat water, paddling, large capacity
In simple, baby, new-be, amateur, for dummies, new to, and patient language please help with these:
1. What would be the widest beam width practical, at the paddlers location?
2. Seat height vs. side height.
3. How wide could the bottom be with tumblehome sides?
4. Rocker vs. no rocker
5. Short/wide boat vs. longer/narrow boat for increased capacity

beekeeper

 

[gbinga]

This should be a good thread. I'm still trying to figure out how high I want the seat to be in my UJ pirogue. Been experimenting with boat cushions, even spent some time sitting on top of my tackle box Saturday.

I'm guessing that it will matter whether you are using a single paddle or a kayak paddle on a couple of these questions.

George

 

[Jimmy W]

My old Blue Hole canoe was about 35 inches wide and I paddled it from the center when solo. The seats were just below the gunnels about 12 inches high. That was alright in flat water. I would always get off of the seat and kneel in whitewater. In the South Wind 15-30 and my pirogue which are both close to 30" wide, I use a seat about 8" high. The narrower the boat the lower the seat as a rule. Lower will be more stable.
The bottom could be about 36" wide, but I personally would rather have narrower for flat water. It depends on what you are comfortable with. Wider will be more stable.
Rocker or no rocker would depend on how much you want to be able to spin it around or track straight and that also depends on hull shape. Both my South Wind and my Touring Pirogue-T have similar amounts of rocker, about 1" of each end, but the pirogue will spin around quickly when lightly loaded and the South Wind won't. Of course you asked about flat bottom boats and the South Wind is more rounded.
As a rule, long and narrow will be faster and more efficient to paddle. All boats have trade offs, you just have to decide what traits that you think are most important to you. Then build a shed full like Mick so you can use the best one for each situation like a golfer using different clubs for different shots.

 

[Kayak Jack]

Criteria; flat bottom, pirogue or narrow beateau type boats, flat water, paddling, large capacity
In simple, baby, new-be, amateur, for dummies, new to, and patient language please help with these:
1. What would be the widest beam width practical, at the paddlers location?
2. Seat height vs. side height.
3. How wide could the bottom be with tumblehome sides?
4. Rocker vs. no rocker
5. Short/wide boat vs. longer/narrow boat for increased capacity

Length is usually the best way to increase capacity. Lower Center of Gravity (CG) is a good way to increase stability. Changing from flat to semi-rounded bottom is the usual way to improve predictable stability, and speed. Keeping a flat bottom is useful for swamps and very shallow backwaters, but damned little else.

 

[JEM]

Lots of factors here that are interrelated. And much of it depends on you. Maybe getting a baseline for comparison would be the most helpful. Is there a hull you've paddled that you can give comments about how it felt for you? Any chance to rent something local to you that you could try?

I'll give some general comments from what I like:

#1 and #3 are related. If you have a tumblehome panel, then the boat can be wider with the widest part closer to the water. That's going to give you a nice stable ride. I think Seedtick has a yellow pirogue he built like that.

#2. This one is also related to #3. If you have a tumblehome panel, harder for water to get in and you can lower the sides. I'd say side height minimum of 11" and max of 14". That's just my comfort level. I know Chuck likes his around 10". Lower seat height equals more stability but higher seat equals easier paddling as you can stroke the paddle in the water with less effort.

#4 More rocker if you need it to turn fast much of the time. Less rocker for straight line paddling over distance. Can compromise with more rocker up front and less aft.

#5 Capacity: Capacity and length are closely related. If ... IF .... you don't have a specific length needed for gear, here's how I feel you should get your ideal boat length:

-a) Figure you capacity number,
-b) figure the max width and shape of the hull cross section you want
-c) then stretch or shrink the length as needed to fit your capacity needs.

Those are just my preferences. Many different ways to skin that cat.

 

[oldsparkey]

#2. This one is also related to #3. If you have a tumblehome panel, harder for water to get in and you can lower the sides. I'd say side height minimum of 11" and max of 14". That's just my comfort level. I know Chuck likes his around 10". Lower seat height equals more stability but higher seat equals easier paddling as you can stroke the paddle in the water with less effort.

Talk about extremes .....or ... For what it is worth department.....
I know one person who makes his at 8 inches but it is not recommended for others to do that. He has spent all his life in paddle craft with 8 inch sideboards. Needless to say , he does not get into rough water , just the quiet back waters.

Then there was the one individual who made a pirogue at 25 feet. He does guided swamp tours.

Chuck.

 

[beekeeper]

Some more ideas. Thanks to all who replied.

1. My seat is 10.5" high, seems about right comfort wise, and for casting. I'm still experimenting.
2. At the seat's present location my boat has a 32" bottom,14.5" sides flared at 22.5 degrees. It is doable but would be
better if not so wide. It is 38" bottom and 44" at the rails max. width.
3. I wanted to keep the length short for ease of hauling in my truck. I know this may not be possible and keep the
capacity I need. I weigh 300 lbs. My boat 's capacity is 500lbs.
4. I don't know the amount of rocker my boat has. It does turn easily, but is hard to paddle straight and it drifts bad
when fishing.
5. Kayak Jack wrote

Keeping a flat bottom is useful for swamps and very shallow backwaters, but damned little else.

My boat will be used in swamps and very shallow backwaters, but (my Mama said this was not a nice word :wink: )
little else.

beekeeper

 

[JEM]

I threw together a rough sketch for ballpark numbers.

You'll need about 12' x 40" max beam, with the max beam within a few inches of the water. minimal rocker. Tumblehome as desired.

 

[beekeeper]

Thanks Matt.

beekeeper

 

[JEM]

Here's the sketch I threw together the other day. It's just a shell and would need gunwales, end caps, seat(s) and a couple of thwarts.

As drawn it would fit the parameters you mentiond. But I have no idea how how the individual panels would fit out on standard plywood sheets, hull weight or anything like that. I didn't put much time into it.

Regarding tracking, it's a short boat with a flat bottom. With 500 on board, she might need some bottom runners to help keep it real straight. Or maybe glue on a little "end-skeg/stem" on one or both ends. It would be easy to just duct tape them on for a trial run before gluing and fiberglass taping permanently.

Again, it's just a rough sketch.

 

[seedtick]

Just a thought

you might want to consider a skiff, just like a pirogue only has a transom on the back instead of a pointy end

adds a little more stability and has a larger water footprint so a heavier person can wiggle around more comfortably

 

[JEM]

Skiff is an option. But not sure if there's one out there that would paddle any better than your Gator Boat.

 

[beekeeper]

Matt
I like your sketch. If I'm following correctly, the boat could have an aprox. 32" to 38" bottom, flared to about 40", and then tumblehomed (is that a real word?), with a total side height of 11" to 14".

seedtick
Lots of builders modify the Croc, for use with motors or oars, by not tapering the stern. I didn't because it would have been too wide to paddle. Any idea what size (bottom width, beam width, side height, length,etc.) skiff would work?

I removed the bench seat and paddled some using the lower temporary sliding seat. I need more paddling time to decide on any conclusions. Right now the boat tracks best when paddling with the stern going forward. Go figure?

beekeeper

 

[JEM]

the hull that got the displacement numbers you first mentioned had a 30" bottom flared to 38". It was just some lines I threw together that happen to work. If you squared it off instead of double-ended, you could reduce the length a bit.

 

[seedtick]

we pattern our skiffs after our pirogues

the front half is the same as a pirogue, 14' long has a 24" bottom - can easily be wider if you want to add a motor or want more load capability, sides flare out 25 to 35 degrees at midpoint and the back tapers to a transom with about a 16" bottom - can be narrower if you don't want to hang a motor on back. Just like any other boat, all sorts of flexibility on dimensions. Don't know that's there is any formula out there that will input your wish list and spit out the "perfect" boat for those parameters. You give up manuerability for tracking, speed, ease of paddling for stability, cxapacity, etc. That's why so many folks end up building more than one

next time you're in Bass Pro, check out the skiff we built for them

 

[beekeeper]

seedtick
Looked for the skiff at B.P. recently. Didn't see it this time but I have befor. The two pirogues had $1.99 baits displayed in them. I guess the boats make the baits look good. What a waste!
I forgot to measure my boat at the beam where I sit to paddle, but the sides are too wide or too high for efficient paddling. Any idea or estimation of the beam width and side height for a skiff? I would like to sit 8" to 10" above the floor.

I know I am asking a lot of questions, but I want to do better on my next build by making better choices.
Less rocker= less maneuverability, but better tracking, correct? Could be a good thing, right?
Speed is less with a boat that tracks straight? Why? Has anybody actually paddled two similar boats, but one with rocker and one with out or less rocker? If so please post your views.
I believe I understand a wider ( more stable, higher capacity) boat will be harder to paddle, but I can't change my needs much or I want be able to use it.

Thanks to everyone for their input and patients.

beekeeper

 

[gbinga]

Could you consider oars? Or is that impractical for the places that you fish?

Oars could be used for main propulsion, with a paddle on board for close quarters or minor adjustments.

If you could use oars, extra width is not a problem.

George

 

[JEM]

Speed is less with a boat that tracks straight? Why?

speed isn't directly related to a boats tracking ability. In general, a paddling hull that tracks better will seem to move FASTER because your energy is being used for forward propulsion and not so much to keep it straight.

 

[Jimmy W]

Speed is less with a boat that tracks straight? Why? Has anybody actually paddled two similar boats, but one with rocker and one with out or less rocker? If so please post your views.

beekeeper

I think that a boat with less rocker that tracks better will probably be faster.
George is right. A good row boat might suit you well.

 

[beekeeper]

George
When I posted my paddling and drifting around problems on the Gator Boat forum the primary reply was that most Crocs(model of my boat) used outboard or trolling motors. If not they used oars. If I can't make paddling work with my current boat I will resort to the trolling motor. Didn't want to, because one of my goals was no paper work and minimum hassle ( slide boat out of truck and go). Oars may would work, but I'm not familiar with rowing. The trees are extremely close together where I fish, and sitting backwards would probably not work with my style of fishing.
Like most builders befor I finished the first build I knew I would probably do another one. With the information given I believe I can build a boat that can be paddled in a practicable way and meet my other needs.

beekeeper