Measuring wall thickness underwater is a challenge. There are two options for taking measurements;

50 Foot Underwater Probe / Cable Assembly

1. Use a standard gauge with long underwater probe. This method requires 2 people, one on land with the instrument and a diver with a communication device. For this method we offer a 50 ft under water probe -> https://www.checkline.com/product/TI-25-UW-50

Underwater Ultrasonic Thickness Gauge

2. Use of an underwater ultrasonic thickness gauge. This method only requires 1 person, a diver with a waterproof, submersible thickness gauge. For this application we offer our TI-UMX2 -> https://www.checkline.com/product/TI-UMX2

Are you looking to test high capacity manual torque wrenches? If so we recommend our new TT-QCM torque tester. It is available in capacities up to 2000 lb-ft / 2700 Nm with accuracy of ±0.25% of indicated. It is made in the USA and is supplied with a traceable calibration certificate. Learn more about our TT-QCM here -> https://www.checkline.com/torque_testers/TT-QCM

Torque Wrench Tester