Have you found it around town cheaper than Diesel? Everywhere I looked a few years ago it was 5 to 10 cents more. That alone put the thought out of my mind.
Pearson Fuels - B99
4067 El Cajon Boulevard San Diego, CA 92105
619-243-0456
$4.45 per Gallon for B20 (20% bio, 80% diesel) (Updated 2012-01-24)
I paid $4.15 for red dye diesel on Wednesday at So Cal truck stop so you're better off putting that in the boat.
Mike
http://en.wikipedia.org/wiki/Biodiesel some info on the blends and applications pertaining to warranty issues on some vehicles.