As Paul implies the folks who developed these craft had no deck openings except the cockpit coaming(s). Their intended use was hunting and not transport. When they felt it time to move camp they used their larger open skin boats to carry their families and baggage. So I guess we're asking our kayaks to do something not in their nature.

If we want to transport ourselves and a minimum of essential gear we may have to make changes that are like converting a formula car to a SUV. This requires some compromise in design. I guess what bothers me the most about hatches is the weakness introduced to the structure by cutting those holes in the stressed skin deck. I've never seen a hatch design that has enough framing added to make up for the weakness introduced by the hatch opening. By the time you'd got your box section framing built in to restore the hull's strength you'd have lost a lot of storage space.

Just a couple of thoughts on floatation. As we all learned in April 1912 the term unsinkable is often overused. The J/22 is a sail boat that displaces 1800 lbs., 700 lbs. which is lead. Mindful of the Titanic, it is not advertized as unsinkable. However, two internal bouyancy tanks provide enough floatation to keep the deck above water with the hull swamped. The tanks have 8" inspection ports. Nevertheless, one of the boats went down during last winter's Nationals due to the owner's failure to maintain the integrity of the tanks. During the '60's and 70's Pearson yachts built a 23' keelboat called the Ensign displacing almost two tons. It had a large open cockpit which presented a serious danger of swamping and sinking. The builder created two bouyancy chambers which it filled with two-part ureathane foam. After several years this foam absorbed enough water to make it ineffective as floatation. A number of these boats surprised their owners by sinking out from under them. I sailed in a Rebel 16' which had both foam and tanks for bouyancy. When swamped it wouldn't sink, but in any kind of chop two of us with buckets couldn't keep ahead boarding seas either.

The lesson here is that no system designed to keep water out of a floating object is fool-proof. Foams have to be close-celled and kept away from solvents. Tanks, inspection ports and bladders have to be inspected for soundness and leaks. Lastly, systems to remove water should be provided for and also properly maintained. I just read of a yacht which was lost when her pumps failed because the last party to use it swept their trash, including match sticks, into the bilges. The match sticks jammed the pump's valves. Another reason not to smoke.

So I guess I'd think twice about making it any easier for water to get into my boat.