People been capsizing all lengths of canoes since they were first created back to the dugout canoes.
I have always had 16.5 foot solo prism or 17 foo-t tandems canoes. Much to with stability has also due to width and design also.
But was wondering can a canoe get to long and make it more vulnerable to capsize. I could see controlling different size canoes maneuverability is effected.

What is your expert opinion from those whom used 16 to 20 foot canoes. I know solo a 16.5 foot canoe is ideal for me alone. How do the big footers operate with 2-3 people?
I have zero experience in them windy or calm water.

The most important element is experience and when to stay put on shore in windy conditions.

Lets hear from you experts.

Interesting questions, and don't consider myself to be an expert, but in response to your first question. I don't believe a longer canoe would be more vulnerable to capsizing. In big waves I think bigger is more likely to be better. Easier to maintain your speed and less likely to get caught between waves. I do adhere to discretion being the better part of valor and like to sit out big waves.

I have paddled a Winona MN 2 with the BW Rangers, as well as a MN 3 alot. I hate to be the duffer in a 3 seat canoe, but in my experience, if you want to plow through some waves, a 3 person with experienced paddlers has it.
Can't say much about trailing seas but the MN 2 took some 3+ foot trailing seas one time on Perent.

I am in the same boat as you. I have the 16.5 Prism and a Spirit II. I've paddled Northstar and Souris River models also, but no personal experience with large canoes. I've seen several groups while in the BWCA with the bigger models and a lot of it seems to come down to the experience of the paddlers. Always makes me nervous seeing the families out there with two smaller kids in the middle seat.

I have a Wenonah Seneca 3-seater used for family trips and the occasional odd numbered adult trip (although I usually prefer to be in my solo these days instead of a 3-seater). At 19'4" and almost 40" wide the Seneca is a bus with an almost flat bottom that I can stand up in.

It's more boat than I care for in most situations and as my kids get older, they will be moving to their own tandem, but for now it serves its purpose. I would never say it couldn't capsize but with 3 adults paddling and a lot of freeboard it doesn't get much more stable than this.

That being said, taking it out on the water without gear in higher winds with a less than experienced paddler is not a lot of fun.

Not an expert, but have paddled a lot of canoes in the larger class.

The tension of ballast and freeboard is the equation I focus on, given experience warrants being out in wind at all.

1. Ballast has to be pushed, so the paddlers have to be up to it.
2. Freeboard is only an advantage if there is enough ballast to hold you down while you push through wind/waves, instead of being pushed around and struggling just to maneuver.
3. Back to ballast, it increases surface area below waterline and therefore drag which lengthens the crossing and increases danger when excessive.
Yes. Vicious cycle.

So...My answers?
Average paddlers (x2) with a week of gear 16-18 ft. OR (x3) 18-20 ft
Large paddlers (x2) with a week of gear 17-19 ft. or (x3) 18.5+ ft
4 adult paddlers will always need a 19.5 ft boat unless at least two of them are quite small.

Caveats:
Large to me means a minimum of 200 lbs with adequate reach. 6ft 190 is average. Small means 125 lbs or less, with short reach.
Kids under 14 don't count in my reasoning, unless they are exceptionally dependable and proven trippers. Too little breakfast or too many squirrels turn them into ballast.
If you're extra large like me (325 lbs over 6 ft), count yourself as 1.5, and smile when you maintain a line while others are bobbing and spinning.

Length only serves as an advantage if paddlers are experienced AND if ballast is proportionate. A longer plow only digs deeper. A longer plane needs more engines and thrust.

Skill and luck are not substitutes for good sense and caution. Knowing your crew is just as, maybe more important than knowing your boat.
Think safe, be safe.

My J200 back in the day had next to no initial or final stability. It was 18' 6" never capsized it. I Think hull shape and the paddler have more to do with it.

For big waves, I worry less about length and more about hull shape and behavior. I don't like skinny fast canoes in big waves because they are more likely to slice through a wave and take water over the gunwales. I prefer a canoe that will bob up and over the waves more. I don't like my Wenonah Advantage with big following waves because they grab the more extreme tumblehome and make it wobbly.

bfurlow: "I am in the same boat as you. I have the 16.5 Prism and a Spirit II. I've paddled Northstar and Souris River models also, but no personal experience with large canoes. I've seen several groups while in the BWCA with the bigger models and a lot of it seems to come down to the experience of the paddlers. Always makes me nervous seeing the families out there with two smaller kids in the middle seat. "

Why does kids in a middle seat make you nervous? I've had all three of my kids share the middle seat in a Q18.5 and I'm not sure how that was any more or less dangerous than any other options... Seriously wondering what your concern was...

Used a Souris River 18.5 foot canoe in the Woodland Caribou Provincial Park with three people and all the gear. 5 Day trip. Weather was the usual bit of everything. I remember the last day being a bit rainy and choppy. Never really had any concerns. I do remember the long boat loaded down was a bit more challenging to turn and maneuver, but it was a joy to portage--if one can say such a thing.

I would think that the length of the canoe would have no difference in the ability for it to tip. You can have long skinny canoes that tip easily or short wide ones that are very stable. Maybe if it held more weight and you loaded it down with a low center of gravity, then a bigger boat might be more stable. I do think hull shape is more important.

For the 2 kids in the center of the canoe. I think that is more because they are inexperienced kids and can move from one side of the canoe to the other quickly, causing the canoe to tip. I'm going to put my 2 kids in the center, and yes, I am worried about them sitting still.