What Does “+ / - 1 Month” Mean in a Seafarer’s Contract — and Who Actually Controls It

What Does “+ / - 1 Month” Mean in a Seafarer’s Contract — and Who Actually Controls It

The phrase “+ / - 1 month”, often found in the Period of Employment section of a Seafarer’s Employment Agreement (SEA), is one of the most common — and most misunderstood — terms in maritime contracts.
Many seafarers believe that this flexibility applies equally to both parties.
In reality, this clause exists for the benefit of the shipowner, not the seafarer, as defined under the Maritime Labour Convention (MLC 2006) and ITF / IBF collective agreements.

1. What “+ / - 1 Month” Actually Means

When a contract states “6 months (+/-1 month)”, it means that:

• the basic service period is 6 months;

• the shipowner has the right to shorten it by one month (5 months total) or extend it by one month (up to 7 months).

This flexibility depends on operational needs — voyage schedules, port of crew change, visa or travel restrictions, weather conditions, or commercial reasons.👉 It is crucial to understand:
this clause is not the seafarer’s right, but rather the owner’s operational discretion.
By signing the contract, the seafarer agrees to this possible variation.
The “+/-1 month” formula exists solely to protect the shipowner and to provide legal flexibility when crew changes cannot occur exactly on schedule.

2. Legal Basis: The Maritime Labour Convention (MLC 2006)

According to Regulation 2.1 “Seafarers’ Employment Agreements”, every SEA must specify:

• the duration of service on board,

• the conditions for extension or termination,

• and the seafarer’s right to repatriation at the end of the agreed period.

Standard A2.5.2 (b) of the MLC 2006 clearly states that:

The maximum period of continuous service on board following which a seafarer is entitled to repatriation shall be less than 12 months.

In practice, this means the seafarer must be repatriated within 12 months of joining the vessel.
Therefore, a “+/-1 month” variation is valid only if:

• it was clearly stated in the SEA,

• and the seafarer gave informed consent upon signing.

Any extension beyond 12 months without the seafarer’s written consent constitutes a violation of the MLC and may be treated as unlawful detention on board.

3. ITF and IBF Position

The International Transport Workers’ Federation (ITF) and the International Bargaining Forum (IBF) recognize the “+/-1 month” term as a management right belonging to the shipowner.
Typical ITF/IBF clause wording reads:

“Normal duration of employment: 6 months (+/-1 month at Owner’s discretion).”

The key phrase — at Owner’s discretion — defines that the flexibility applies only to the shipowner, not to the seafarer.
However, ITF and IBF collective agreements also provide protection to the seafarer:

• any extension must be documented in writing;

• the seafarer retains the right to repatriation after the agreed basic term;

• all extra days must be paid proportionally to the salary and leave entitlement;

• and the total service period may not exceed 12 months.

4. Why Companies Use “+ / - 1 Month”

Maritime operations are unpredictable — schedules, ports, and charter commitments constantly change.
Weather delays, visa issues, or lack of relief crew may also affect crew rotation.
Therefore, the “+/-1 month” clause serves several essential functions:

• allows legal flexibility in planning crew changes,

• prevents formal contract breaches due to operational delays,

• and ensures compliance with MLC and IBF standards without risking penalties.

In short, it’s a practical tool that reflects real-life conditions of the shipping industry.

5. Seafarers’ Rights Within “+/-1 Month”

Even though this clause favors the company, the seafarer’s core rights remain protected under MLC and ITF:✅ The seafarer has the right to repatriation within 12 months of embarkation.
✅ Any extension beyond the agreed range requires written consent.
✅ Additional days must be fully compensated.
✅ Forced retention beyond 12 months constitutes an MLC violation.
✅ The seafarer may file a complaint through ITF or the flag state representative if held on board against their will.

6. What Seafarers Should Understand

• “+/-1 month” is not a benefit but a right of the shipowner to adjust the duration.

• The seafarer should read and understand this clause carefully before signing.

• If unwilling to extend, the seafarer must formally notify the company before the end of the main term.

• All changes should be recorded in writing and confirmed in the Sea Service Record.

7. Conclusion

The “+ / - 1 month” clause is not about shared flexibility — it is an operational management tool that protects the shipowner’s ability to manage unpredictable shipping conditions while remaining within international labour standards.Nevertheless, under MLC 2006, every seafarer is entitled to:

• repatriation no later than 12 months after joining;

• voluntary agreement to any contract extension;

• and full payment for all additional service time.

Understanding this clause empowers seafarers to know their rights and prevents misinterpretation.
Remember: “+/-1 month” does not belong to the seafarer — it belongs to the shipowner, bounded by law, respect, and fair practice.