Holy geez, a Grummun!!
We may have already had this conversation, but how do I know? -- I have one so recognized the blue bit.
Nice trip boats but heavy sobs (76, 78 lbs, can't recall)
It is an 18 foot lightweight, I think it is 66 pounds. I do not recall if that weight is with or without the portage yoke. The skin is quite thin, I think it is 32 thousandths of an inch, where the standard (heavier) model was 50 thousandths. Easily flexes, so you do not want to do any white water. Nine ribs in the bottom due to the thin skin. I think it is mid 70s vintage if I recall correctly. I bought it new in early 80s, but this one had sat in the canoe yard for a few years before I bought it.