Purpose - The design and construction of a high-pressure bursting strength tester is described. Design/methodology/approach - The tester has a large aperture and is intended to operate with coated industrial fabrics. To ensure safe operation, since the tester is capable of operating up to pressures of 5,000 kPa, water is used as the inflation medium and all tests are conducted under water. The tester is designed to operate on both flat specimens and cylindrical specimens. Findings - Sample results are reported to demonstrate the successful operation of the tester on plain specimens and on specimens with welded and taped seams. The tester has demonstrated that it is capable of yielding reproducible and useful results on coated industrial fabrics of the type used to manufacture inflatable boats. Practical implications - The low-cost, high pressure bursting strength tester can be used for lightweight, coated industrial fabrics of the type commonly used in the construction of inflatable boats and liferafts. Originality/value - The tester was developed to support a programme of work to develop a lightweight, collapsible decompression chamber. Although the parameters of the tester were chosen to meet the needs of the decompression chamber project, the tester has wider application and may, therefore, be of wider interest.