Can you use sea toilets on the River Great Ouse?

There are essentially three types of toilets that can be used on boats; sea toilets which discharge waste directly into the water, toilets incorporating a holding tank for waste and portable chemical toilets. The Great Ouse and its tributaries, the Nene and the Middle Level are all fairly unique in allowing the use of sea toilets. These toilets have an inlet and discharge valve in the hull, pumping waste directly into the river. The second system is the sea toilet with the waste discharged into a holding tank. The holding tank has to be emptied at a pump out station which are available at a few marinas as well as the Environment Agency stations in Earith and Ely. The third system is the portable type toilet where a small flushing system and holding tank are contained in the unit. The holding tank needs to be filled with chemicals that break down the waste bacterially and the cassette needs to be emptied after a weekends use and can be done so at most marinas. Please note that if you are buying a boat and intend to transport it to a different waterway it is wise to check the local regulation regarding toilet use.