I've never run the Knik. I've got an 18-ft Jon, 48-in beam with a 60/40 Evinrude. I had a 40 HP yamaha prop on it and I just got the 60/40 jet. I'm wanting to get some runs in before winter!
To give you my level of experience, I've ran the 20-mile a few times. Both as a passenger and a driver. Ran it last Saturday and had a great time.
How are the water levels on the Knik right now? How does it compare to the 20-mile in difficulty, depth, obstacles, etc.