By Don Casey
Revised by BoatUS editors in April 2012
This fan isn't for the engine, it's for you. When you think about it, it is just human nature to extract yourself as soon as possible from an uncomfortable environment--a hot engine compartment, for example. Having air blowing over you when you do engine maintenance makes the task more pleasant, and it makes it easier to give a job the time it needs. Both engine and disposition benefit.
You don't need a designer fan for this use. An inexpensive 12-volt automotive fan is perfect. Mount it where it can draw in outside air and blow it in your face. A lighted switch outside the engine compartment is a good idea so you don't forget to turn the fan off when the job is finished.
If the best position for keeping you cool puts the fan in an otherwise inconvenient location, install the fan on a wedge mount. With two bracket sets, you can run the fan where it does the most good and store it where it is least in the way. Additional bracket sets will let you move the fan to other areas of the engine compartment. A clip-on mount also allows moving the fan around. If it will be at risk of jumping out of the brackets or coming unclipped when you are underway, pin it in position with a bolt or a length of hardwood dowel. You can also remove it to a storage locker, but this will drastically reduce the its use.
One word of caution if you have a gasoline engine(s). This type of fan is not likely to be ignition protected, so always make sure the engine compartment is fume-free before you switch on the fan.
For more enhancements for your boat, consult 100 Fast & Easy Boat Improvements by Don Casey.