Ron, I had the same problem with my Expedition Single, though not as severe. My deck was wider than the hull by as much as 3/4" ea side. Most severe at ends, least at mid-section. I was partial to bead and cove strips in anticipation of this problem. I put a bead of epoxy in the cove (hull) right before installing the deck. Starting in the middle, I popped the beaded deck into the coved hull and wrapped a bungie cord around the mated pair. Repeat this roughly at every station as you work towards the ends. It went pretty smoothly, although the last 16" or so of the deck just would not fully fit into the cove. Stuck out 1/8" or so, even tried bar clamps to condense the deck further to no avail. Just planed off the excess in the end. Got good seam taping inside and out at these areas, so I think it will be fine. I agree with Nick - FORCE IT! Heat sounds like a viable option as well. This created one bad side-effect, the hatch covers want to maintain the shape of the deck BEFORE it was condensed. I even rigged them with weights in the correctly sprung position and let them sit for weeks in my garage where the temp fluctuates a lot, (during hard cure) didn't seem to help. Still workin on the problem, may spring hatch to correct position, then add layer of glass while clamped and allowed to cure. Good luck. DC