sweeeeeeeeeeeeeeeet! i just talked to chris, and the dimensions are for a "V Drive Sac". He said that when the bags are full of water, the dimensions 14x14x42 will stretch to 16x16x42, if not further.
So how cool is that, I didn't mention this earlier, but those dimensions were for two sacs I have in my rear lockers. So I have more weight in my boat then I thought I did. It's not every day you wake up and find out you actually have more weight.
Feels like Christmas in July.