Richard Ferguson wrote:

Sounds like you guys have made up your mind that CG is the issue, and
that adding weight to a boat can't possibly make it unstable, and that I
don't know what I am talking about, so I think I am wasting my
breath/typing.

Richard, if you're sincere in your desire to understand this (and I
believe that you are), you can't allow yourself to get frustrated when
you get answers that you don't understand or don't agree with.

Let me make one last try to support my position.

1. My friend, who is kind of a skinny guy, but is about the same height,
had no problem with the kayak. He is not an expert kayaker. We later
went out offshore into some waves in the Pacific ocean, he in that kayak
and me paddling a windsurfer hull, neither of us had problems, we went
snorkeling, and then climbed back on and paddled back in. This was not
an ultra-narrow high performance narrow sit on top, it was a cheap
recreational type of sit on top, which one would expect to be pretty
stable.

Fine.

2. If the center of gravity is the issue, how come my buddy had no
problem with the boat, and I could not keep it upright for 10 seconds in
flat water, once I lifted my legs out of the water? I am not that bad a
paddler, and since he is the same height, his center of gravity would be
about the same. But maybe you guys think that I am not only incorrect,
but an incompetent paddler. That is probably the only way you can
logically defend your position.

There is no need to get defensive. There is a difference between being
competent and being comfortable in a specific boat. When I first started
paddling, I did so in a fairly wide boat (24" beam). I learned a lot of
skills and felt that I was reasonably competent. When I switched to a
narrower (22") boat with a rounder hull profile, it was like having to
learn all over again. It took months before I was as comfortable in it
as in my wider boat. I now paddle boats that are narrower and
considerably less stable comfortably and that old 22" feels like
paddling a sofa.

It's not a matter of competence. It's a matter of getting used to a
particular boat. If you're used to a wider and/or more stable boat, your
body is used to making relatively coarse movements and large weight
shifts in the course of paddling. Those same movements and weight shifts
in a less stable boat will cause greater movement of the boat, making it
feel unstable. Once you get used to the finer movements necessary in the
less stable boat, it will feel comfortable. It's simply a matter of
adjustment. If you were to paddle a less stable boat for a while then
get back into your old one, it will feel like a barge.

3. He warned me before I tried it that I would probably have trouble
with the boat, that I was too heavy for the boat. He said that his
daughter usually used the boat, and the boat was probably sized more for
her than 200 pound men.

Perhaps so, but if you didn't sink it, that's not what made it feel less
stable. It's probably simply a less stable boat that you're not used to.

The only way to settle this issue scientifically would be to take that
boat with a medium weight paddler, and gradually add weight to the boat
to make the total weight (paddler plus dead weight) equal to around 200
pounds, and see how the boat performed. Obviously I think the boat
would become unstable, and you guys think that the boat would not become
unstable. Since you have never seen a boat become unstable with heavy
loads, you think it can't happen, but it happened to me.

You're simply misinterpreting your experience Richard.

I have loaded my camping boat until it had less than 1" of freeboard
(distance from the gunwale to the water) and it became more stable. I
have 2" or less of freeboard in all of my boats and they're quite
stable. It's a common recommendation for owner of high volume touring
boats to add weight to them to increase stability when they're not
loaded with gear.

How many more examples do you need?

As I said, you guys are not going to listen to me, so I will shut up. ;-)

Open-mindedness goes both ways. If you're not willing to listen to the
answers you receive, why even bother to ask a question? If all you want
is validation of your opinion, you won't find it here, since it's
incorrect. We're trying to help you understand what you experienced. If
anyone should listen, it should be you, don't you think?

You have a choice. You an cling to your belief or you can listen to the
information that's being offered to you. What you do is entirely up to
you. Just remember that you cannot make something true simply by
refusing to believe that it's not.