Get the stargazer and you don't have to worry about cutting a hole for the paddle wheel. I just bought it from onlyinboards.com
http://www.onlyinboards.com/perfect-pass.html The system took me 2 hours to install the linkage part was a bit tricky but simple enough after all was said and done. I don't regret getting the stargazer even though I already have a paddle wheel speedo. I could have gone either way without having to cut a hole in the hull. Ian was awesome to work with and I got my box the same week. I recommend, top notch guy, service, and product.