Three different numbers appear in guidance on liferaft servicing. They apply in different circumstances.

Guidance on inflatable liferaft servicing refers to 12-month, 17-month and 30-month intervals, and the three are sometimes treated as alternatives to choose between. They are not.

Twelve months is the baseline. SOLAS Chapter III requires inflatable liferafts to be serviced at an approved station at intervals not exceeding 12 months. This is the interval that applies unless something specific permits otherwise.

Seventeen months is an extension, not an entitlement. Where servicing at 12 months is impracticable, the administration may allow the interval to run to 17 months. In practice this is used to align raft servicing with the vessel's survey window rather than sending rafts ashore twice in one cycle. It depends on the flag agreeing, and it is not something to assume.

Thirty months applies only to rafts specifically approved for extended service intervals, and comes with a condition: an onboard inspection in the intervening year. An ESI raft is not simply a raft that gets serviced less often — it is a different approval with its own regime.

The reason this matters at inspection is that the certificate has to match the basis being claimed. A raft presented on a 30-month cycle without ESI approval, or with the intervening onboard inspection missing, is a finding. So is a raft on a 17-month cycle where the flag's permission cannot be produced.

Confirm the applicable interval against the flag and the raft's own approval before planning the attendance, rather than working from the date on the last certificate.