101welcomw aboard Oldman. Your not the only Oldman here. Some will claim they are "older than dirt" and others that are younger will say "getting old". However your never too old to learn fishing techniques.
Your on track with your equipment with exception of float tube which jigging would not be out of reach. A boat would be more suited with downriggers for trolling and to cover more of an area in search of kokes. Kokes comfort zone is 52° and during summer months they go deeper as surface temps warm and constantly moving around. A float tube would be a bit much when you have to search for kokanee out on the deep. Also, when the season arouses to it ice fishing is another avenue to get you over those active areas. There is a lot of good information here that can get you going. My suggestion is to hitchhike on another boat or 2 to get a feel for techniques used.
Tight Lines and will be looking fwd. to your adventurous posts. Feel free to ask questions as there are answers awaiting..