You are not permitted to download, save or email this image. Visit image gallery to purchase the image.
About 23 council staff tested their readiness during the exercise which simulated a response to an environmental incident.
They used two boats to carry oil-spill booms to contain the spill before using equipment including ''skimmers'' to clean the floating oil.
Staff were not told the details of the scenario ahead of time.
Council environmental services manager Martin King said it held the exercise to get staff thinking about different ways to improve operations.
''Like, we have a vessel that's leaking, how do we encapsulate that efficiently and effectively?''
The council creates similar simulations twice a year.