Their Ultrasonic Thickness Gauges, which include a range of measuring instruments for surface and underwater applications, use multiple-echo technology that has become the industry standard for ultrasonic accurate measurement. They have recently developed a new range of gauges that incorporate single-echo and echo-echo measuring modes using twin crystal probes, which can assist in obtaining measurements in areas of extreme corrosion or back wall pitting. Cygnus' surface thickness gauges are ATEX approved intrinsically safe gauges for use in hazardous areas, and they also offer hands-free gauges designed for climbing or rope access work, general purpose gauges with A-scan display and sequential data logging, and more advanced gauges with A-scan and B-scan display, comprehensive data logging, manual gain control, Bluetooth, and other features. Their underwater thickness gauges include a diver wrist-mountable data logging gauge, an ROV mountable range depth rated up to 4,000 meters with optional probe handling solutions, and the original RINA approved divers hand-held gauge depth rated to 300 meters. They also offer an ultrasonic hatch cover leak detector for testing weather tightness of cargo hold hatch covers and door seals.