I think about this all the time. Recently we have been averaging about 10% sailing in our trips around RI/MA south shore. It just seems that whenever we are heading for a new harbor the wind is either too light to sail (under 5 kts) or from the wrong direction (on the nose or dead down wind). So we motor a lot. That's the down side. However, we motor at almost 8 kts and it's quiet in the cockpit and enjoyable. I've been on many power boats and almost bought a trawler type when I bought my current boat Maxine. What drove me away from the trawler was the noise. I didn't want to climb up to a fly bridge (neither did the dogs) so I wanted a main deck control station. In test driving these types of boats it was like the hammers of hell down below so you would be driven to the fly bridge. So on a 40 mile trip a power boat, like a lobster yacht type, may average 16 kts, let's say, so it takes them 2-1/2 hrs running plus an hour in and out of harbor for 3-1/2 hrs of noisy mind numbing travel. In my boat, that trip takes 5 hours running and an hour in and out for six hours, 2-1/2 hr difference. Even powering my fully enclosed cockpit is quiet, relaxing, and the view is great. So we arrive rested and eager to explore, a difference of 2-1/2 hrs big deal. And of course there's the fuel burn. We use about a gallon an hour. The power boat uses anywhere from 4-6 on up. And, as a bonus, some days we actually get to sail Try that in a power boat.