MK I
The Mark I was the original. It featured a stepped deck and large cockpit The cabin bulkheads are 14" further forward on the MK I than the MK II so the cockpit is larger and the cabin is smaller. Somewhere between hull #40 and #75, they started to add the spinnaker and Genoa winch on the combings. The cabin on the MK I does not sit flush with the hull giving a very small place to put your foot on the MK I. Also, all MK I's had an aluminum side brace inside the cabin to stabilize the keel trunk.