Re: A sail and human power boat for the great loop
In my experience, people who genuinely, actually, regularly go sail and oar cruising without any engine for any sort of distance are very few and far between. In fact I know all three of the other guys who live in Washington State who do it. 
But an awful lot of people find it an interesting subject to talk about. I think that's great! More people should experience the immersive and rewarding experience of relying on your own wits and resources rather than on twisting a throttle. It's as different as driving your car through an artificial Safari Park versus actually hiking the PCT with a pack on your back. Or like skiing at a managed ski-resort with chairlifts and groomed runs versus heading into the backcountry. Going as fast as possible or with the highest tech, expensive gadgetry isn't the point--it's doing it by your own skill and determination that is most enriching and fulfilling.
I have to agree with Terry that the ICW seems like a dreadful place to practice this esoteric art though. For the same amount of time and money invested, you could go somewhere where you'd encounter a hell of a lot less powerboat wakes, noise and pollution. Fewer biting insects too.
Amphibious Macroplankton Oughtredia doublendus
Mostly found frequenting the littoral and estuarine zones in the southern half of the Salish Sea, though sightings have been recorded both north and south of this area, and occasionally, but rarely, inland, in freshwater environments. This species lives on micro-brewed beer and dutch-oven biscuits,and displays brightly colored nylon and gore-tex plumage during the rainy season. Approach with caution!