Thanks for the welcome, Robert, but it's a little late. I have visited this site on a daily basis and have posted hundreds of times since the time you were regaling us about turning a kayak into scrap on a waterfall drop. How long ago was that?
More on topic, if someone says they need a really lightweight boat to be able to cartop you have to accept their judgement.
Stuff like this,
"I can lift all my boats on the car without
difficulty on my own - and that includes commercial fibreglass boats, which
are heavier.",
doesn't get to the heart of the problem posed by the guy who started the thread.
He said he had a problem solo lifting boats onto a roofrack. Saying something akin to , "I can lift X,Y or Z, why can't you?" is rather disengenuous.
I can dead-lift a 35 lb. boat onto my pickup but not a 45lber. I just can't. I might be able to do it if I lifted weights for 6 months but my arthritic shoulders might not survive the process.
One more thing. When I was 50 years old (a long time ago) I ran a 3:50 marathon. Why can't you, Robert?

: Easy going, Charlie. Andy has said nothing callow but has only tried to
: advise according to his experience, which is excellent. Thus far you have
: had excellent advise from the good folks here at Guillemot. There are
: others here who are even older than you are so there is no point to
: playing up the old man sensibilities. We are all getting older here. I
: will be hitting 50 soon enough myself. Many of us here have spent many
: years splitting white water down to its basics. Andy has often given good
: advice and I don't see that he has made any errors yet. Give the man and
: inch and he'll share all of his experiences you need. Take what you want,
: leave the rest. I for one, ache all over the place and I, for one, will
: keep doing the crazy things I do till my body wears out. I gather you
: aren't done yet so heed the advice you read and take the best that suits
: you.

: Welcome to the gang, Charlie, I think you must be new here since I don't
: recall you in the 9 years I have been with this group at this site.

: Robert N Pruden
: Edmonton, Canada