RE: Anyone know what this is? Ice boat?
I agree, you will want firmer snow to get some speed, I assume you don't want to build larger skis. And find a site with more room, that's a pretty short area for run up. Too, try waxing the skis, that can make a big difference. When a ski runs on snow it melts the surface, which can freeze to the ski and add a lot of drag. Check with any cross-country ski shop, they'll help you choose a good wax. Once you find a firm surface to run on I'd try an APC 10x6 prop, that always worked best on my .45-powered air boats.
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