Define it before you measure it
Off-hire is the scoreboard of technical management. Everything a technical manager does — maintenance, spares, superintendency, crew competence — exists to keep the ship earning. When it fails, the ship stops earning and the number is unambiguous.
Under a time charter, off-hire arises where the vessel is unable to perform the service required, in the circumstances set out in the off-hire clause. Precise wording varies substantially between charterparty forms, and the difference between "any time lost" and "full working of the vessel" wording is commercially significant.
For internal management purposes, adopt a consistent definition and cause taxonomy:
| Cause code | Includes |
|---|---|
| Technical — machinery | Main engine, auxiliary, steering, propulsion |
| Technical — cargo systems | Pumps, cranes, hatch covers, reefer plant |
| Technical — other | Navigation, communications, ballast |
| Scheduled dry docking | Planned, in the docking window |
| Repairs outside docking | Planned repairs taken between dockings |
| Crew | Manning shortfall, certification, medical |
| Detention / deficiency | PSC or class-driven stoppage |
| Waiting for spares | Where it extends a repair |
| Owner's convenience | Non-technical |
Report unplanned technical off-hire separately. It is the number that measures management quality; total off-hire including docking measures the docking schedule.
Calculating true availability
Available days = calendar days − scheduled docking days − off-hire days Availability % = available days ÷ (calendar days − scheduled docking days)
Then express cost per available day rather than per calendar day. A vessel with lower daily OPEX and fifteen days of unplanned off-hire is not the cheaper ship.
Machinery dominates, which is unsurprising. What is more informative is the tail: crew, detention and spares delay together commonly account for a quarter or more of unplanned off-hire, and none of those are engineering failures. They are planning failures.
Targets worth setting
| Metric | Indicative target |
|---|---|
| Unplanned technical off-hire | Under 3 days per vessel per year |
| Off-hire events per vessel per year | Under 2 |
| Mean time to restore | Falling year on year |
| Off-hire caused by spares delay | Zero |
| Off-hire caused by crew/certification | Zero |
| Detention days | Zero |
Two of those targets are absolute zeros, and both are legitimate. A ship that goes off-hire because a spare did not arrive, or because an officer's certificate expired, has been let down by an administrative process, not by an engine.
Reducing it
1. Critical equipment discipline. Under the ISM Code, equipment whose sudden failure could create a hazardous situation must be identified and its reliability promoted, including regular testing of standby arrangements. Standby equipment that has never been tested under load is not standby equipment.
2. Condition monitoring. Vibration analysis, lube oil analysis and thermography catch developing faults while they are still repairs rather than casualties.
3. Spares staged against PMS due dates. Not ordered when the job starts.
4. Certificate control with blocking. No assignment that would place a seafarer aboard with a document expiring mid-contract.
5. Root cause on every event. Including the near-misses — the failures that did not quite stop the ship.
6. Sister-ship propagation. A failure on one vessel is a warning about the others. Check them.
The commercial mechanics
Off-hire is not automatic; it is a claim. Owners should:
- Record the exact times of loss of service and restoration, with evidence
- Understand whether the clause is a "net loss of time" or "period" form, because the difference can be days
- Distinguish partial from total loss of service — cranes out of action may be partial
- Preserve engine room logs, alarm printouts and repair records contemporaneously
- Address the interaction with loss of hire insurance, including the deductible period
Loss of hire cover is worth reviewing against actual off-hire history: a deductible longer than the fleet's typical event duration means the cover almost never responds.
off-hire entitlement is charterparty-specific; this is general information, not legal advice. Distribution chart is an indicative model. Reviewed by the Zeaclub Editorial Team, 24 August 2026.
Frequently asked questions
What is off-hire?
A period during which a time-chartered vessel is not earning hire because it is unable to perform the required service, as defined in the charterparty's off-hire clause.
Does dry docking count as off-hire?
Usually it is dealt with separately under the charterparty. For internal measurement, keep scheduled docking apart from unplanned technical off-hire — they measure different things.
What is a good off-hire performance?
Fewer than about three days of unplanned technical off-hire per vessel per year is a reasonable benchmark for well-maintained mid-age tonnage, with zero attributable to spares delay or certification.
Is off-hire the manager's fault?
Not always, but it is the manager's responsibility to analyse and reduce. Recurrence without root cause analysis is the failure, not the first event.