William Atkin designed Katydidn't and included her in his book Motor Boats, published by The Macmillan Company in 1937. In this he wrote, "One needs a dinghy that will be towed most of the time -- but occassions arise when it becomes best to get the dink on deck or in the cockpit. I know of no other plans for a dinghy so small as this and so economical to build in the amateur workshop, or have built professionally. Mr. W. J. McElroy has had a Katydidn't built by Ole Amondsen at Greenwich. It seems to be entirely satisfactory, rows well with one or two aboard -- and will carry three in smooth water.
"Now in such a tiny boat as this, there is no way in which to correct violent changes in trim caused by passengers -- the weight of the load is out of all proportion to the displacement of the boat. So don't anticipate rowing off to sea in her. Katydidn't is not a rowing boat -- rather, she is the smallest practical boat in which to get ashore from or aboard a cruiser. Nor will she sail -- and by the same token she is not a life boat.
"Katydidn't is a round bilge pram type dinghy, and is of a size that can be towed without effort, lifted aboard if necessary, and is so light as not to require a giant to move her about. The length is 6 feet 6 inches, the breadth 3 feet 4 inches, the depth 1 foot 1 1/2 inches. The stern is 2 feet 9 inches wide; the bow 1 foot 10 inches. Katydidn't is flat floored of the round bottom model, and in smooth water will carry three average weight people, and two in reasonable safety.
"There is an after seat. The other extends fore and aft and is supported on the bow and on a stanchion and panting beam amidships. Thus the oarsman by shifting from the after to the forward pair of row locks maintains trim with one, two, or three persons aboard."
John Atkin redesigned the strip-planked Katydidn't for cold-molded construction and renamed the design Petey Dink CM.