As I pictured the suggestion, the resulting tool would be an elongated L-shape with the board forming the long part and the spike or nail forming the short part, except that the nail would not be set in the extreme end of the board, but rather an inch or two away from the end. The end would then be wrapped or treated some way to strengthen the spike and keep it from pulling out under stress. A piece of plastic or minicel foam would be a sacrificial cap for the sharp point of the spike, and a line would be attached by which two such tools would be secured to the boat.

After reading the replies above, I think I personally would prefer the “dowel-type” or screwdriver-shaped implement that scafool tells how to make, and that seems to be represented by the ebay link. In fact, being a big fan of multi-use tools, I think it’d be cool to have actual screwdrivers with long handles and short blades – say 6-inch handles and 3 inch long, 1/4-in-diam blades, one Phillips and one regular. I especially like the idea of keeping them in your sleeves, as one of my objections to the other type was the extra time required to get them after capsize and before swimming to shore.

One thing I’m not clear on is what type of ice is possible at the point you are trying to climb out. Based on a video I saw and one poster’s comment above about “punk ice”, it seems possible that the ice within reach could be too rotten to hold the small blade. In that case, the L-shaped tool would give you a few feet extra reach, which might be a decisive advantage.