While at sea or in port, the hull of a ship can be an attractive new residence for all sorts or creatures. The initial slime build-up can provide a welcome mat for more and more creatures. This 'biofouling' can end up being inches think and heavy in weight as well as stopping the streamlining of the vessel. The drag caused can result in more fuel being needed to keep the ship moving forwards at the same speed - more cost and more carbon. Tom Heap meets a new stowaway on ships which will help fight the build up. Paint company Jotun has now developed the Hullskater robot. Monitoring of conditions will alert when the robot needs to be deployed on missions - with its magnetic wheels and high definition cameras it inspects the surface and uses brushes to remove the build up. With an increasing fleet of ships, Dr Tamsin Edwards from Kings College London also reflects on other measures to keep hulls free of build up and alternative fuels that might help the international fleet reduce its carbon impact. Producer: Anne-Marie Bullock Researcher: Sarah Goodman Produced in conjunction with the Royal Geographical Society. Particular thanks for this episode to Professor Bharathram Ganapathisubramani from the University of Southampton.