Ranger, congratulations on your new Adventure! Here are some things to look for for the skeptics among us....
Last 4 numbers of the serial # tell when made and year model. K809 was built Nov '08, but is an '09 model. C909 was built March '09 and is also an '09 model.
Hobie prominently stamps all their demos on the top areas of the cockpit in at least 2 places with the letters DEMO -- you can't miss them. Inspect the hull. If a boat has been out, there is almost always telltale scuff marks on the bottom.
The boats are normally packaged, as are the Drives. Tell your dealer if you want to be there for the unwrapping.
Look for the brass insert on the Drive sprockets (where the fin masts are attached) and the term "V2" stamped on the side of the sprockets to make sure yours is an '09 Drive. That's important if that's what you're paying for.
There should be a signed factory check list of everything included -- Drive, seat, gear bucket, paddle, dry bag, manual, etc.
Keep in mind that many dealers unpack your boat, pre-inspect it, make adjustments if necessary and go over everything with you.
Enjoy your new boat!
