Too tender

[Eddiebou]

I went down to the pond the other evening. My neighbor had left his 6 hr canoe and paddle there by the edge of the water.

Cool, I thought. I'll go for a ride.

I flipped the little boat over and set it in the water. I could see footprints in the bottom, so I stepped onboard. There was a rope dragging from the bow so I stepped toward it to haul it in.

Within seconds, the bow went under water and 40 gallons or so poured in. I tried to steady the boat with the paddle on the bank but, Man, this boat was TIPPY! I decided the best thing for me to do was get out of it. By now there was 8 inches of water in the boat and my pants were all wet.

I mean, this boat is probably 15 feet long, maybe 3 ft wide. Another friend of mine had built it about 10+ yrs ago and covered all sorts of ground in it. My neighbor's wife bought it for him for a christmas present about 8 yrs ago and it's been hanging in his shed ever since. He had told me it wasn't as stable as a 16' rail skiff that I had built.

So, I had posed a similar question on here some time ago:

For a given hull design, If you build one out of thin plywood, etc. and build another one out of solid wood, 3/4 boards, etc. Which one will be more stable? I'm guessing the solid wood one. Why? The weight alone?
My solid wood rail skiff is practically the same size as the canoe, but it is 10 times more stable. I can stand and pole that boat over logs and walk around and carry a dog, a buddy, and 2 dozen decoys without a care. The plywood canoe is so tender I'd just about be scarred to sneeze.

Comments?

[TR]

Eddie,

Weight and VCG (vertical center of gravity) has some to do with it but in this case waterplane area has much more. I think the 6hr is double-ended? If your skiff has a transom her waterplane is just much larger and thus stability greater. Of course in the lighter boat as you move to one end the waterplane gets tiny (where it might not in a heavier design) and stability the same, as most of the hull is in the air........

[Phil Y]

Much more to do with shape than weight I think. Thats probably what Tad is saying too. But weight will come into it-if the boat weighs almost nothing and you put all your weight in one end, the other end will lift up a lot more. You then have a really odd shape in the water. If the boat has some weight to it, not so much will happen as you move your weight to the end. I think there'd be some sort of leverage factor involved.

[Eddiebou]

I hear what both of you are saying. But this is where I'm going with this:

So you take the lines off a traditional boat and decide to build it out of thin ply f/glass etc. You build it and now it's so light and unstable it is unsafe.
For instance you can't move forward to adjust sail trim like you would in a traditionally built boat. Yes, there's a build on the forum right now that caused me to think of this.

I am not a designer/engineer. I just wonder about the practicality of some of these super-lite "car-topable" boats. I mean, I like to be on a boat and feel like I've got something under my feet. That's one of the things I like about wooden boats.

[Ian McColgin]

Eddiebou, I think you miss the whole point of form stability and boat design. The six hour canoe has a narrow beam at the waterline and nothing in the ends. Of course she's tippy if you stand. If you sit, she's nice and stabile and you can carve your turns (lean out) rather nicely. You can make her heavy if you want but that will have no effect on the stability since the weight of the paddler is so great, as in significantly greater if the paddler is adult, than the weight of the boat.

There are boats where how they are laden matters much. A friend made a very faithful replica of a working Maine pea pod. The boat was a crank, tending to gripe (turn on her bow) and very twitchy. Recalling that it was a lobster boat and that the old timers started with the boat ballasted with rocks which were thrown overboard as lobsters were pulled in, I experimented with just shoveling in about 500# of beach stand, which trimmed her about right and she rowed well.

The hull construction is not ballast and has little effect on stability assuming you don't go to extremes like making huge high heavy topsides. Your problem with the six hour canoe is not how she way made by with your understanding of boats.

[James McMullen]

Eddie, I'm sorry, but that was 100% operator error. The Six Hour Canoe is essentially an undecked sea kayak. It's not designed for standing up and walking around in, it's designed for sitting your ass down amidships and paddling with a double-bladed paddle. There's nothing wrong with that boat if you use it correctly.

[hokiefan]

I have a Cheap Canoe which is a very similar design to the 6-Hour Canoe. I would only stand up in it if I wanted to go swimming.

Cheers,

Bobby

[Bobcat]

I have a six hour canoe and treat it like a kayak. You get in from the side with your weight right where it's going end up. You keep our weight low. There's lots of stability once you're seated.

[skuthorp]

My double ended Mac canoe has a round section and can be very tender without ballast. I can and do stand in it but very carefully. She is much more stable under sail however.
My sea kayak is not nearly so forgiving. With practice I imagine you could stand in it but as I said, very carefully.

[Ian McColgin]

Standing in a kayak shaped boat is more easily done dynamicly just as staying up on a bicycle is easier in motion than stopped. If you're in a stabile surf down a wave and can get up and then stay up far more easily than if you try it at rest. Similarly, there are those who have modified white-water kayaks with a waterproof hatch just abaft the cockpit, the bottom of which has the hull protected by slats. This allows the paddler to stand and pole the boat upstream over moderatly serious rapids, a surprisingly easy exercise that lets you take a good look at the stream before running it. Partly these boats are a nudge more stabile in this use than a sea kayak would be, but again much stability is due to the dynamics of being in moving water. Much harder to poll down stream.

[johngsandusky]

That all makes sense. I do agree that very light boats have shortcomings. I don't like a rowboat much under 100 lbs, especially in a tender.

[Eddiebou]

Eddie, I'm sorry, but that was 100% operator error. The Six Hour Canoe is essentially an undecked sea kayak. It's not designed for standing up and walking around in, it's designed for sitting your ass down amidships and paddling with a double-bladed paddle. There's nothing wrong with that boat if you use it correctly.

Yes, James...You're 100% correct. LOL There was more operator error in the 60 seconds I spent in that boat than you can imagine!

Some funny things have happened to me down by the pond. I was standing in a liitle aluminum boat fishing one day when I set the hook and lost my footing and tipped over. My head went underwater and everything else stayed dry. I think I even landed the fish. I had to laugh out loud just thinking of how silly it would have looked.

Another time I rode my bike down there to wet a line. I had my rod & tackle box in my right hand. My approach was so quiet and sudden that I didn't see the gander of a pair of geese that were nesting. The gander jumped into flight to defend the nest. To avoid running smack into him, I naturally squeezed the brake with my left hand, which operates the FRONT wheel brake. Over the handlebars I went, face first into the ground. At least I didn't fall in the water.

[skuthorp]

Standing in a kayak shaped boat is more easily done dynamicly just as staying up on a bicycle is easier in motion than stopped. If you're in a stabile surf down a wave and can get up and then stay up far more easily than if you try it at rest. Similarly, there are those who have modified white-water kayaks with a waterproof hatch just abaft the cockpit, the bottom of which has the hull protected by slats. This allows the paddler to stand and pole the boat upstream over moderatly serious rapids, a surprisingly easy exercise that lets you take a good look at the stream before running it. Partly these boats are a nudge more stabile in this use than a sea kayak would be, but again much stability is due to the dynamics of being in moving water. Much harder to poll down stream.

I paddled K1's for years and the club coach would make us get the boat up to speed and try to stand. Only moderately successfully! But Reg's work paid of in that any boat is comparatively stable after a K1. I try to balance the boat stationary if I can, I must try try standing in the rear cargo hatch as you suggest. Any excuse to get wet.

[Cuyahoga Chuck]

Wailing about the Six-Hour Canoe is a waste of breath. It is a poor design. It was designed by two university profs in Buffalo as part of a social uplift program. They did ok with the little they knew. But it has way too much rocker and way too much top hamper.
I paddle a plywood pirogue (Cheap Canoe) that is similar in shape but designed by an NA. You can't stand up in it, ever, and a seat in it had better be no more than 4" off the bottom. I paddle mine kneeling but most builders install a backrest and sit on the bottom. It's the nature of the dory shape. My bottom is only 22" wide and I and the boat don't weigh enough to get the boat more than 2" down in the water so a low center of gravity or a lot of body english is essential.
Even if the Six-Hour was drawn properly it would probably still be tippy.