Seattle's own Foss Maritime has developed a new generation of tugboats that use less fuel and generate less pollution than the older versions.  The LA Times had an article on a new hybrid that will be used extensively in maritime operations, especially in California.  The ports of Los Angeles and Long Beach, the largest cargo container ports in the nation, have about $5 billion in expansion projects on the books, which they cannot build unless they are able to mitigate pollution. 

The ports, together with California's South Coast Air Quality Management District, provided $1.35 million in development costs to Foss. 

Tests have shown that a hybrid tug is likely to reduce particulate and nitrogen-oxide emissions by about 44%.  Foss has been working to develop such a tug for a couple of years.  They knew that tugboats tend to run on full power only 7% of the time and they waste a huge amount of energy by idling 50% of the time.  They had to address the issue of the batteries being too heavy and found a solution similar to one used on "ultra-deep-water" drilling rigs that runs the diesel engine and the electrical motor generator through the same drive shaft, allowing for smaller batteries and smaller diesel engines. 

The new tugboats look and drive like normal tugs.