I have a 1960 Tunneled Lowe Roughneck with a 115/80 Yamaha jet. I am looking into purchasing a new/used kicker. In the past I've borrowed a 25 hp evinrude (prop) that has worked great but I hate having to borrow things. My question is, what is enough hp to get me safely to shore if I have engine trouble, and can I get something with enough power with an internal tank? I take my boat above the bridge on the Copper dipping, on the Big and little Su, Talkeetna, Kenai, etc...basically most types of fast moving glacically fed rivers. Thanks for any advice ahead of time.