The 10/77 rule is a rolling-window and record discipline, not a simple total.

Keep STCW watch and safety-duty scope distinct from MLC seafarer records, and review the normal rule, exceptions, actual work record and endorsement chain separately.

Written by: Faromo · Product and maritime domain teamReviewed by: Faromo · Technical and regulatory reviewLast reviewed:

First determine which rule applies to whom and under which record regime.

STCW Code Section A-VIII/1 addresses rest arrangements for watchkeepers and personnel with designated safety, security and pollution-prevention duties. MLC Standard A2.3 permits national implementation based on maximum work or minimum rest; under the minimum-rest basis, the normal limit is at least ten hours in any 24 hours and 77 hours in any seven days. Faromo’s current calculation scans only the minimum-rest basis.

“Any 24 hours” is not a calendar day; the window can start at every hour. The planned schedule should be posted onboard, the record should reflect actual work and rest, it should be endorsed by the master or authorized person and the seafarer, and a copy should be given to the seafarer. Deviations for drills, call-outs and emergencies should remain visible, with required compensatory rest managed separately.

As of August 2026, the 2025 MLC amendments are not in force and are expected under the ILO timetable to enter into force on 23 December 2027. This guide applies the current normal 10/77 rule; flag-State implementation, collective agreement and company procedure must still be verified.

Build rest-hours control across four distinct evidence layers.

The normal threshold, actual record, authorized exception and endorsement are not the same thing. This model places official requirements beside what Faromo currently checks.[1][2][3][4][5][6]

STCW A-VIII/1

Watch and safety duties

Rest arrangements apply to watchkeepers and personnel assigned safety, security or pollution-prevention duties; watch systems must not impair efficiency through fatigue.

MLC A2.3

Normal minimum-rest basis

Where the national regime uses minimum rest, ten hours in any 24 and 77 in any seven days are required; the minimum ten comprises no more than two main periods, one at least six hours, with no more than 14 hours between consecutive rest periods.

MLC RECORD

Schedule, actual record and dual endorsement

The onboard work arrangement should be posted; the standardized actual-hours record should be endorsed by the master/authorized person and the seafarer, with a copy provided to the seafarer.

OVERRIDING

Deviation and compensatory rest

Emergencies and calls involving ship, person or cargo safety, or assistance at sea, may disrupt the normal schedule. The deviation should be recorded and adequate compensatory rest provided to affected personnel.

Control matrix

Separate official requirements from current product behavior.

Verify which window, data and approval scope is actually covered when saying the system performs a check.

ControlOfficial / operational requirementWhat does Faromo do today?Record producedExplicit boundary
NORMAL 24HAt least ten hours of rest in any 24 hours.Joins consecutive days into an hourly timeline and advances the 24-hour window one hour at a time.Window start/end, lowest rest and threshold.Uses hourly resolution; it is not a 15-minute or official-form equivalent.
NORMAL 7DAt least 77 hours of rest in any consecutive seven days.Checks total rest across consecutive seven-day blocks.Seven-day window, actual total and 77-hour threshold.With fewer than seven complete consecutive days this check produces no result; no violation is not proof of sufficient data.
REST SPLITThe minimum ten hours comprises no more than two main periods; one is at least six hours.Scans the minimum number of periods needed to make ten hours and the longest period in each 24-hour window.Period count, longest period and relevant window.An extra rest period alone is not treated as a breach when two qualifying periods already make up the minimum ten.
DAILY vs RANGECompliance must be assessed on rolling windows; a calendar-day summary is insufficient.The range API performs rolling checks; the day badge in the monthly grid calculates each day separately.Range violations and day-level denormalized flags are kept separately.A clear daily grid does not mean cross-midnight or seven-day range checks passed.
DATA GAPRecords should completely reflect actual work patterns.Breaks the timeline at a missing day and makes no assumption across the gap.A result calculated only from available consecutive blocks.Missing days are not automatically “rest”; a skipped window is not evidence of compliance.
70H EXCEPTIONAn authorized exception is conditional on duration, reuse, split and rest-interval limits; flag implementation must be verified separately.The current extendedException option only lowers the weekly threshold from 77 to 70.Weekly result against a 70-hour threshold.It does not fully validate exception eligibility, two-week limits, cooldown or three-period conditions; it is disabled in the public tool.
EMERGENCY / DRILLDeviation should enter the actual record and required compensatory rest should be provided.Hour blocks, overtime and remarks can be recorded.Daily hour record, remark and overtime field.There is no linked corrective-action workflow for emergency authorization or compensatory rest.
ENDORSEMENTThe record should be endorsed by the master/authorized person and seafarer, with a copy given to the seafarer.Finalization adds one authorized-user timestamp and locks the range.finalizedAt and finalizedById.The current model is not dual seafarer-plus-master endorsement or a copy-delivery workflow.
FORECASTSchedule changes, actual records and fatigue risk should be assessed together by an authorized person.A pure forecasting function exists in the codebase.There is no user-facing planning record or alert screen yet.No claim is made that the current product warns users before a violation.

PSC procedures may examine records, schedules and actual arrangements; incomplete/inaccurate records or threshold departures may become deficiencies. Detention is not an automatic calculation result but an authorized PSCO judgment.

Before onboard use

Ten-point rest-hours acceptance check

Accept the system against the full evidence chain below, not merely because it “calculates 10/77”.[1][2][3][4][5][6]

  1. SCOPE Which regime applies to whom?: Confirm STCW duty scope, MLC seafarer scope and the national maximum-work/minimum-rest basis for each vessel.
  2. FLAG / CBA Record local and agreement terms: Do not replace flag instructions, CBA, company procedure and exception authority with one generic assumption.
  3. SCHEDULE Post the planned arrangement: Display sea and port work arrangements and minimum rest limits accessibly in the ship’s working language and English.
  4. ACTUAL RECORD Record call-outs and deviations: Do not force drill, pilotage, cargo operation, defect, alarm and unexpected call-out hours back into the plan; enter actual events.
  5. COMPLETENESS Do not treat a missing day as compliant: Quality-check complete days, blank hours and the presence of seven consecutive days for every person.
  6. ROLLING WINDOW Move from day badges to range checks: Review cross-midnight 24-hour windows and complete seven-day totals separately in the range report.
  7. EXCEPTION Evidence authority and duration: Do not use the 70-hour option as a generic tolerance; document flag/CBA authority, start/end, split conditions, reuse limit and cooldown.
  8. COMPENSATION Link deviation to close-out action: Close an emergency or drill deviation with its reason, authorized review and compensatory rest provided.
  9. ENDORSEMENT Verify both parties and the copy: Evidence seafarer and master/authorized-person endorsement, dates and delivery of a record copy to the seafarer separately.
  10. PSC PACK Reconcile schedule, record and explanation: Confirm that the posted schedule, actual hours, exception/deviation explanations, compensation and endorsements agree for the same period.

This checklist does not grant legal compliance or flag approval. The vessel’s flag State, collective agreement, SMS procedure and authorized inspector’s judgment remain determinative.

Educational tool · normal rule

Seven-day rest-hours pre-check

The interactive browser tool pre-checks a 168-hour work-rest schedule against rolling 24-hour and seven-day normal thresholds.

Scope boundary

An hourly educational pre-check, not an official record, 70-hour exception, flag/CBA interpretation, emergency handling, compensatory rest, dual endorsement, legal-compliance or PSC decision.

Scope and core capabilities

1. Hourly actual record

The current day editor stores 24 one-hour work/rest blocks, overtime and remarks. This resolution is not presented as equivalent to an official form.

2. Rolling range check

The range service scans cross-midnight 24-hour windows and complete seven-day blocks across consecutive days.

3. Data-gap boundary

A missing day breaks the timeline and windows across the gap are skipped. The result should not be treated as compliance evidence without a separate data-sufficiency indicator.

4. Actual-record context

Overtime and remarks can retain context, but there is not yet a linked CAPA flow from a violation to compensatory rest.

5. Single-user finalization

Finalization locks the range and stores one authorized-user stamp; it is not dual seafarer-plus-master endorsement or copy delivery to the seafarer.

6. Forecast not exposed

The forecasting function in the codebase is not wired to a user interface or operational workflow. The current product is therefore not described as warning before a violation.

Workflow

  1. Set the rule basis: Confirm flag, CBA, duty scope and the national maximum-work/minimum-rest basis.
  2. Separate plan from actuals: Retain the posted schedule while entering call-outs, drills and operational deviations into the actual record.
  3. Review range and completeness: An authorized person reviews rolling 24 hours, complete seven days, missing days and split conditions together.
  4. Close deviation and endorsement: Complete authorized exceptions, compensatory rest, dual endorsement and the seafarer’s copy with separate evidence.

Operational outcomes

  • Expose cross-midnight windows that calendar-day totals miss.
  • Separate insufficient data from a false “compliant” result.
  • Avoid treating the normal rule and an authorized exception as the same tolerance.
  • Present schedule, actual record, deviation, compensation and endorsement together in the PSC pack.

Frequently asked questions

Does “ten hours in 24” mean a calendar day?

No. The ILO’s 2026 MLC FAQ explains “any 24 hours” as a rolling period beginning at any moment. A 00:00–24:00 total alone is therefore insufficient.

Can the ten hours of rest be split into more than two periods?

Under the normal rule, the main rest making up the minimum ten comprises no more than two periods, one at least six hours. An extra rest period alone is not a breach when two qualifying periods already provide the minimum ten; authorized exception conditions are assessed separately.

Can everyone use the 70-hour exception?

No. It is not a generic tolerance. Authorization, duration, split, consecutive-use and cooldown conditions must be verified against the applicable STCW implementation, flag and any CBA. Faromo’s current option only lowers the weekly threshold and does not validate full exception eligibility.

How does a drill or emergency call affect the record?

Actual work time should enter the record, with the basis for deviation and required compensatory rest tracked separately. The current Faromo record can retain remarks but does not provide a linked compensatory-rest close-out flow.

Does Faromo finalization satisfy MLC endorsement requirements?

Not by itself. Current finalization is a single authorized-user stamp; it is not dual seafarer-plus-master/authorized-person endorsement or delivery of a record copy to the seafarer.

Does the pre-check tool produce an official compliance result?

No. The tool scans one 168-hour input at hourly resolution against normal 10/77 thresholds. Flag/CBA interpretation, the 70-hour exception, emergencies, compensatory rest, fatigue, surrounding weeks, official forms and endorsement are out of scope; it does not replace a legal or PSC decision.

Primary sources