The water tunnel has a small test section 100x100x800 mm, which is under slight pressure (150 mm water). The side and bottom walls are made of 6 mm thick glass for imaging with high energy lasers, and the roof is 12 mm thick perspex. Rails on both sides of the test section, and an optical table below, allow easy mounting of optical components for flow visualisation. A 9:1 square contraction is used together with three stainless steel screens to reduce the background turbulence intensity level in the tunnel (still to be measured). A gate valve and meter allow the flow rate to be continuously adjusted from about 5 - 70 L/min giving a freestream Reynolds number of around 10,000 (based on max freestream velocity and tunnel width). The tunnel is mounted on wheels and can be moved within the lab to reconfigure the experimental arrangement