F14 and I took our 10' Addictor with our new to us 40hp up the Napa River yesterday. We towed it with my "mighty" S10 four banger. I believe our combined HP for both is roughly 162ish but who's counting. We had a blast but next time we are going to be a little more courageous and maybe launch in Vallejo and see the entire river. Maybe, just maybe, someday Brian & I will have REAL boats running but at least we got out on the water. It was low tide when we were going up river but at long as you pay attention to channel markers and really just stay in the middle it's perfectly fine. You absolutely would have to pay real attention to the channel markers at high tide because it could end very badly.