This fan does a great job in both circulating air and clearing the defrost in my class A motorhome. They are powerful yet quiet, and fold out of the way for good vision to the front. They also serve to pull air in the front door to circulate in the coach. Only wish there was a second slower speed.
I put two of these in the v-berth of my sailboat. It is hard to believe that such a loud fan that sounds very powerful could move such an insignificant amount of air. I found that taking the back cover off the fan helped produce a small improvement but not much. I even tried bending the fan blade to produce more pitch but ended up breaking it. Spend more money and get a fan that actually moves air!
Plastics do not belong on a cruising boat. After o.nly a few uses the neck snapped off while trying to adjust the direction - it was supposed to be adjustable - I guess separating the fan head from the base makes it totally adjustable, just not convenient.