Take a cruise from Leigh On Sea to the Eerie World War 2 Maunsell forts, called the Knock John Forts, Shivering Sands Forts & Red Sand Maunsell Forts/Towers. These Historic monuments stand in the Thames Estuary between some 9-15 miles from Southend shoreline and 5-8 Miles from Whitstable. It will take approximately 2 hours to reach Knock John Fort. Transport yourself back to the Second World War by visiting these previously armed towers built in the Thames & Mersey Estuaries to help defend the United Kingdom. They are a pretty surreal sight. You will get the chance to take plenty of photos in and around the towers/forts as our vessel is small enough to pass between and under the structures (you cannot board them).