-- Last Updated: Oct-22-12 10:12 AM EST --
..., I often drive a Honda Civic hybrid and there's a display right on the dashboard that tells when the batteries are charging and by what method (the car I sometimes drive makes use of deceleration, whether by brake application or coasting, as well as engine power). On the highway, all of the power for normal cruising comes from the engine, and the electric motor only kicks in for hill climbing. But you seem to have missed my point. You say these engines are small, and for a reason, which is true, but since I already mentioned the fact that they are not any smaller than those of compact cars years ago, and are a lot more powerful, why do you still insist they don't have enough power to haul boats? Let me guess. You're a young pup and weren't carrying boats back in the days when 50-horsepower compact cars where used for all the same things that modern small cars are used for. Back when I was doing such things, having 75 or 90 horsepower would have been an unbelievable luxury, not a "handicap". Of course in those days we didn't expect to be able to go 85 mph on the highway. Going the speed limit was considered good enough.
Wanna know something else? The owner of the car I mentioned above often carries a canoe, and sometimes a big canoe AND a kayak. Wanna know something else? The mileage takes a noticeable hit (just as was true of tiny-engined small cars decades ago) but it still gets much better mileage than any mid-size car running unloaded, let alone with boats on the roof, and there is NO feeling of inadequate power. Yeah, it's not a race car, but it gets the job done, and it does it a whole lot easier than you have convinced yourself would be the case.
Finally, a few people here, including the original poster, stressed the idea that a car which suits everyday needs well and may not be ideal for hauling boats is a wiser choice than choosing a car for reasons that are the other way around, and for some people, this would be compatible with the idea of using a hybrid. As has been said, the biggest problem with the Prius is that it's roof is so poorly suited to mounting a good rack, not that it struggles too much when carrying boats and gear. Gear weight is over-rated anyway. A four-person car carrying two people and their gear is usually carrying less weight than if it were simply carrying four people. At worst, it might be about the same, but normally that will only be true if the people are lightweights (does your portion of gear on a typical trip exceed your own body weight? How about exceeding the body weight of a "normal" American male? (that's about 240 pounds)