Cygnus Underwater Mk4 Ultrasonic Thickness Gauge

Ordering Code: 001-9933/4

The Cygnus Underwater is the original diver held subsea multiple echo Ultrasonic Thickness Gauge. It was designed for use by divers undertaking subsea maintenance and surveys 3 decades ago… and today it is still the industry standard.

The unit is depth rated to 300 meters and it provides an accurate metal thickness measurement through coatings up to 20 mm thick. The bright LED display ensures easy viewing even in poor visibility conditions. The Underwater Thickness Gauge is supplied ready to use as a complete kit with 2 rechargeable batteries in a protective carry case.

Cygnus Instruments builds all of its equipment in the UK using only genuine and original parts and components – including Lemo® Connectors and Peli® Cases.

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  • Ships hulls
  • Semi sub structures
  • Subsea pipelines
  • Offshore structures, jackets
  • Storage vessels, FPSO’s
  • Dock gates, piers, jetties and pipings.
  • many more.


Cygnus Underwater ultrasonic thickness gauge; heavy duty remote 2.25 MHz 13 mm (0.5 inch) diameter probe; nose cone tommy bar; probe locking ring key; 2 rechargeable batteries and battery charger; spare membranes and O-rings; steel test block; lanyard; operation manual; pressure test and calibration certificates; Molykote grease and carry case.


Upgrade Kit A: This topside display option is a hand-held surface repeater. It has a large LCD display in an IP65 sealed housing.

Upgrade Kit B: This uses CygLink (Windows based software) installed on a computer. This displays real-time readings which can then be logged.

Unbilical cable length is specified by the customer up to a maximum of 1,000 m (3,280 ft).

Contact Information



iSubC Diving Equipment Ltd
Units 10 Holly Close
Whitehills Business Park
Westby With Plumptons

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