When I read about the crack the first thing that popped into my head was
C-1/C-2.
These things are designed to hold one or two athletic paddlers and not much more. They are not intended to be used as general recreation boats. They have a definite life span. They are flexible flyers and the folks who race them don't waste time scoping out rapids. If they hit a few rocks on the way to the winner's circle what the hell.
At 18'6" this thing has a lot of room for passengers. Don't let your brother-in-law use it like a ferry boat. With too big a load some more cracks might show up at an unfavorable moment.
Sorry to be such a grinch.
Charlie

: This is a pic of what the boat used to look like. The damage is at the middle
: thwart. It looks like someone may have sat on the edge or something as the
: crack goes straight down and then curves to run parallel to the bilge. The
: length of the crack is probably about 10 inches long.
: The boat was raced extensively by one of the local big guys. The bottom along
: the keel is scuffed up pretty good as well. The stern stem has a small
: hole in it. It just appears that this boat is pretty old and the guy just
: didnt take care of his stuff at all. The thing has to be fitted out as
: half of everything is gone. We have the pieces it just needs to be put
: back together.