It's not about the batteries but, about a zero carbon initiative Vancouver recently dropped due to much of their revenue coming from tourism run by hydrocarbon based fuel tour companies. It's cheaper per ton to run tour ships on good old fashioned fuel becasue nothing else can move tons over water like hydrocarbons. Read the company bio for the engine and you will see they moved from Australia to Redmond and targeted Vancouver becasue of the zero carbon initiative. Which the Mayor who is a global warming worshiper had to concede it would severely impact the tourist industry, probably her future as the mayor. Carbon offsets is the give away.