It's 4 foot by 8 foot Okume, the way it comes, right by the bendy ply bins. Did you happen to mosey on by the Baltic birch by any chance? The price was the posted rate, but you can talk the price down, even if you're not a member of the SD Woodworkers.
The Rockler ply is the standard non-marine urethane glue, thin face sheets, like all standard plies, and the core has voids. If you don't mind the occasional void repair and are careful with the wire, all is fine. That is, were you going to build the yak with it or was it for special pieces? If you want to build the yak, they have the same ply at Frost's in 4 by 8 3/16 and 1/4 I think it's $14.
Check out the door skins at Lowe's at $9 a 4 by 8 sheet, luan face sheet and I think they had birch face sheet on luan and sundry cores, all with possible voids, too. If you make one, you might as well make a spare of each with the cheap ply? How's that for a thought!

: Went by Frost on Saturday and all they had was 2'x8' sheets for $40. Then I
: went over to Rockler on Clairemont Mesa Blvd and they had some very nice
: light maple 2'x2' for $3.99. Problem solved.