http://www.maesco.com/products/racor/r_gas/r_gas.html
I am running one of these on my 327 powered CC utility, and I am planning on installing one (or 2) on the Commander. Partially in answer to the ethanol fuel blues, I figure having some water in the bottom of the tank is one thing, but pumping it all the way to the carb is another.
Since I run the Cumberland River, and many others operate in areas where there are commercial shipping, boats are considered to be in "emminent danger" if they are stranded in a shipping channel. Here on the Cumberland, if a barge comes around the corner and they don't know you happen to be in their path with motors that won't start, it may require you to swim fast (or die). Yes, it is a serious issue. In Tennessee a barge can come around a tight bend in the river, and if it's running downstream, there are few chances it could stop. It could steer onto the bank to avoid hitting your boat, but you get the idea. We never anchor in an area where a barge would come through or give us a propwash when turning around a tight section of the river etc.
Therefore, any filtration that keeps the engines ready to start is not only a convenience, it's a big safety issue too.
Regards, safe boating,
Paul