I just started up a guide service as well in Ohio. I'm from Texas and also checked into it there as well this past December. I have spoken to the Texas Division of Wildlife, Ohio Dept of Natural Resources and the Coast Guard. And they ALL have a different opinion, just like all the posts on here so far. My Brother-in Law was just voted "Game Warden of the Year" for 2010 in Texas. He has been the head honcho for the Houston Bay area for years (he was on the water). His explanation about the 6 pack license is that you only need it if you are on water that is connected to international water. The Gulf of Mexico, the Great Lakes, etc. I was told by the ODNR the same thing. ODNR has no licensing or insurance requirements but each state will be different. I would get commercial insurance, a great waiver, check with your state wildlife / fishing authority and also the coast guard for your own piece of mind. Also I was advised to go as an S-Corp rather than an LLC. My accountant advised that it is much harder to sue you on a personal level with the S-Corp. Keep all the assets in your name, not the company name. You can still right it off but just in case you ever have an issue, you get to keep all your stuff! Hope that makes sense and helps!