Looks cool, first time I've seen it I thought of developing my own where it would keep track if it was User updated or updated by the owner/employee of the gas dock.
Was also going to make it easy for them to update either via the web, via a Desktop App, or via a web service. Would also allow them to advertise to maybe encourage them to keep the prices updated.
I don't know how often boat dock gas changes but I know my corner station changes every couple of hours.
I just updated the Norwalk Cove Marina listing at that site. The last time it was edited was June 2008 when diesel was 4.99, today it is at 2.74 as is the gasoline here. Next delivery i'm told it will come down again.