ISM: does the system actually run the ship
An ISM audit asks whether the Safety Management System (SMS) is implemented, not just written. That means checking that procedures match practice, that non-conformities are raised and closed, that drills are carried out, and that the master's review and management review loops are alive rather than nominal.
Implementation is evidenced by the company's Document of Compliance (DOC) and the ship's Safety Management Certificate (SMC); an internal audit is how you protect both.
ISPS: security that holds up under scrutiny
Security verification covers the Ship Security Plan, the duties of the Ship and Company Security Officers, access control, and the declaration of security where required. The test is whether the crew can demonstrate the plan in practice, evidenced by the International Ship Security Certificate.
MLC: the human element
MLC verification looks at seafarer employment agreements, hours of work and rest, accommodation, food and catering, medical care and onboard complaint procedures. These are increasingly common detention grounds and deserve the same rigor as technical items.
The difference good evidence makes
Reviewing the complete record set, including images, gives an objective, defensible view of a vessel's condition. It is the difference between an audit that reassures and one that genuinely protects the operator.