This article is from the Big Folks Sports and Activities FAQ, by firstname.lastname@example.org (Sharon Curtis) with numerous contributions by others.
Kayaking is great fun! You can do it on inland lakes and rivers,
or you can go sea-kayaking.
There might potentially be a problem if you're pear shaped and
the kayak is decked (has a hole in the top that your thighs have
to fit through). Alternatively you can use an undecked kayak.
Canoes are undecked and more accomodating.
If you are worried about the weight the kayak can carry being a
limitation, use one that two people can go in.
It may be that a spray skirt would be useful if you're in a
rough sea, in that case put the skirt on before getting into the
boat, then attach it.
You may be worried about if the kayak capsizes and you get stuck
in it. The most important thing is do *not* panic. You have more
time than you think. Most people can hold their breath for at least
30 seconds, and most wet exits take less than 5.
A technique you may find useful is once you're upside down, rotate
yourself about the axis from neck to toe, so that your legs are
still in the kayak at the same end, but your torso has now turned
round so that your face is now facing the rear deck of the kayak.
Then you just crawl out of the cockpit along the rear deck and
your lifejacket will take you to the surface.
The first time you attempt a wet exit, have a practice in
waist deep water with someone standing next to you. Arrange a signal
that if you get stuck you'll pound on the hull and they'll lift you up
(rotate the kayak) so you can breathe.
Check out rec.boats.paddle for more information.