Vetus LSS50A Plastic Boat Waterlock 50mmVetus LSS50A Plastic Boat Waterlock (50mm 7. 5 Litres) The Vetus LSS50A is an exhaust waterlock made from synthetic materials. This range of Vetus waterlocks feature a complex design to prevent water flowing back down the exhaust line to the engine when it is switched off, and is particularly designed for coping with long exhaust lines. Coolant water and exhaust gas enter the inlet on one side of the waterlock and exit on the other side, after going