Take notice of the safety signs around Clevedon Marine Lake. Water may look safe, but it can be dangerous. Water depth may be shallower than it seems. Submerged objects like rocks may not be visible – these can cause serious impact injuries. Know the SIGNS. A red ring shape with a line running through it, white background and symbols mean you should NOT do this. There are ‘No Diving’ signs positioned around Clevedon Marine Lake. This means no diving in Clevedon Marine Lake, because most of it is shallow, the water is murky and there may be obstructions on the lake bed.