With memories of spring sailing still fresh, and those days lost to drain holes and slush still hurting, there all solutions a-building.
This one is the more classic skunner in which an old downhill ski is slotted, a mounting system designed and the plate runner dropped down through. In this case the wood cheeks are fastened up from the bottom, and a relief milled in the cheeks to allow for the chocks to pivot.
When crossing a skimmed over drain hole, the nose of the ski fetches up on the far side of the hole before the weight of the runner breaks the ice, drops in and rips off your plank. If the runner does break through the ski will provide some lift on the water, and the nose will get you up and out of the far side of the hole. Denis Guertin had documented this with photos which are pretty conclusive. That certainly is above and beyond the call of duty, but the call of spring sailing is pretty strong, too.
In this case, the stiffeners on the insert runner rests directly on the ski, allowing about 1/2″ of blade to protrude. Aluminum brackets secure the runner to the ski. The tip of the ski extends a foot beyond the front of the runner.
All three of these styles will also help get through shell ice, both sailing through it and in the worse case, pushing the boat through if it’s really deep.
As always this time of year: the iceboat building season starts now!