It's the width of the compartment that interferes with the knee space. My compartment is a bit wide and makes it tough to get in and out except when I tip; nothing intereferes with a quick exit upon tipping. Length can be all the way to the bulkhead but you probably won't be able to reach anything that far in. I made mine as long as I could safely reach. It holds a Nikon SLR with 300mm zoom lens, a digital camera, extra gloves, a couple of power bars and a partridge in a pear tree (small size). I sized it for the camera by measuring the width and height of the camera, didn't think too much about knee space but it worked out well enough. The shape effectively maximizes the space available, like a pentagon so that it fits tight under the deck. I could have rounded the bottom corners a little to make it less painful when my knees bump them. Now that I think of it I'll make that improvement this winter while I'm refinishing the hull (banged up badly this year).

Robert N Pruden