Clean Air USA and our partners in the San Diego waterfront, Pacific Tugboat Services and the non-profit Coordinated Maritime Services of San Diego are working together to bring clean fuel and cleaner air to San Diego's scenic harbors and waterways (see Real Media Video Clip):

San Diego Bio Tug

Biodiesel is a domestically produced biodiesel blend approved and used as fuel for diesel engines. 
It’s better for your lungs and more biodegradable than table salt. Protect San Diego’s precious waterways!

Update: From The Bridge