However, William Barker, Deputy Harbour Master of Littlehampton Harbour, said that real problems lay in the UK harbour authorities not having the necessary statutory powers, unlike their US counterparts. 'The MARPOL regulations don't apply to leisure boats, only commercial vessels and passenger craft carrying over 15 people, he explained. 'This means that the largest number of boaters are free to dump where they like. It is annoying.'

The lack of enforcement powers causes problems with water quality. Mr Barker has already noted in a report that many boaters using the harbour have the same need for clean water as bathers. It is a fact that boaters get regularly dunked, and Mr Barker obviously does not want a verdict of 'sewerage-cide' on his hands after someone jumps in on purpose.

However, the European Recreational Craft Directive, which was brought into UK legislation in 2005, specifies that all new craft containing sea-toilets must make provision for the easy installation of holding tanks. Consequently, planning authorities are now insisting that all new marinas are equipped with adequate pump out stations. Following the report, Littlehampton Harbour is going ahead and installing its own, and Mr Barker expects legislation to catch up soon. Which could mean we soon see more conspicuous 'green streaks' in Britain's harbours.