Dive supervisors are able to inspect all commercially obtained SCUBA cylinders for current hydrostatic test date, internal visual inspection within the past year and ensure the cylinders meet DoT requirements. Which statement is correct?

• A. They may inspect only hydrostatic test date
• B. They may inspect only internal visual inspection
• C. They may inspect neither
• D. They may inspect all cylinders for hydrostatic date, internal visual inspection within the past year, and DoT compliance

Answer: (D)

The key idea is safety rests on multiple checks: a cylinder must have a current hydrostatic test date to prove it can safely withstand pressure, an internal visual inspection within the past year to catch inside corrosion or damage, and proper DoT compliance to ensure the cylinder is legally certified and marked for use. A dive supervisor reviewing commercially obtained cylinders should verify all three aspects for each cylinder. This comprehensive check prevents using cylinders that are past their test, have undetected internal problems, or lack proper regulatory certification. Checking only one aspect or none would leave a potential safety risk, so confirming hydrostatic date, internal visual inspection timing, and DoT compliance together is the correct approach.