Every vessel in class runs on a five-year survey cycle, and every owner eventually has to plan around it - budgeting for a renewal survey, scheduling a drydocking, or simply working out why this year’s survey is more involved than last year’s. The cycle is standard across classification societies because it’s built around the same set of IMO and class-rule requirements, but the practical experience of each survey type is different enough that it’s worth understanding before the surveyor arrives.
The cycle at a glance
| Year | Survey | What it checks |
|---|---|---|
| Year 1 | Annual survey | General examination of hull, machinery, and safety equipment |
| Year 2 | Annual survey | General examination, with follow-up on any prior conditions of class |
| Year 3 | Intermediate survey | Extended examination - ballast tanks, cargo spaces, and machinery |
| Year 4 | Annual survey | General examination ahead of the renewal window |
| Year 5 | Renewal / special survey | Comprehensive survey including thickness measurement and docking |
After Year 5, the cycle resets - the renewal survey becomes the baseline for the next five years, and the class certificate is reissued with a new expiry.
Annual surveys: the routine check
Annual surveys happen in Years 1, 2, and 4, and are the lightest-touch surveys in the cycle. The surveyor carries out a general examination of the hull, machinery, and safety equipment, confirms the vessel is being maintained in the condition it was classed in, and checks off any outstanding conditions of class from a prior survey.
Because annual surveys don’t require drydocking or extensive dismantling, they’re usually attended alongside statutory certificate surveys in a single visit - one of the practical advantages of using a classification society that also holds Recognized Organization status, since a single surveyor attendance can cover both class and statutory items. See our guide to what RO status means for how the two interact.
Intermediate surveys: the mid-cycle deep dive
The intermediate survey, in Year 3, sits between the annual and renewal surveys in scope. It extends the general examination to cover ballast tanks, cargo spaces, and machinery in more detail than an annual survey requires - closer to a partial renewal than a routine check. Owners of bulk carriers, tankers, and older vessels in particular should expect the intermediate survey to involve tank internal examinations and, depending on age and vessel type, thickness measurements.
Because the intermediate survey scope grows with vessel age, it’s the stage where owners most often first encounter substantial repair recommendations - worth planning for rather than reacting to.
Renewal (special) survey: the full reset
The Year 5 renewal survey, also called the special survey, is the most comprehensive of the cycle. It’s the point at which the class certificate itself is due to expire and be reissued, so the survey has to establish - not just spot-check - that the vessel remains fit for class for the next five years. That typically means:
- Drydocking, to examine the underwater hull, sea inlets, and rudder.
- Thickness measurement of hull structure, particularly on older vessels or those with a history of corrosion.
- Full examination of machinery, including opening up for internal inspection where the survey scope requires it.
- Closing out all outstanding conditions of class before the renewal certificate is issued.
Because of the scope and the drydocking requirement, renewal surveys need the longest lead time to plan - both to book a drydock slot and to budget for any structural or machinery work the survey identifies.
Planning around the cycle
A few practical points make the cycle easier to manage:
- Survey windows have tolerance, but not much. Annual surveys are due within a window around the anniversary date, not on the exact day - but running past that window puts the vessel at risk of losing class.
- Docking surveys can sometimes be split. Depending on the class rules and vessel type, the drydocking requirement within the five-year cycle can sometimes be split into two dockings rather than one at renewal - worth discussing with your surveyor if drydock availability is tight.
- Combine attendances where possible. Scheduling an annual or intermediate survey to coincide with statutory certificate renewals, or with a planned maintenance period, reduces the number of separate surveyor visits a vessel needs.
MY Classification’s surveyors attend at ports across Malaysia and ASEAN, at short notice, for any stage of the five-year cycle. See our ships in operation service page for the full survey scope, or request a quote to schedule your vessel’s next survey.