Once on Demurrage, Always on Demurrage: Meaning, Exceptions & Examples

“Once on demurrage, always on demurrage” is one of the best-known principles in voyage chartering. In practical terms, it means that once the charterer’s allowed laytime has expired and the vessel enters demurrage, the ordinary exceptions that previously stopped laytime from counting will generally no longer stop the demurrage clock.

A Sunday that was excluded during laytime may now count. Rain that stopped a weather working day calculation may no longer protect charterers. A holiday that previously suspended laytime may also fall within the demurrage period.

But the phrase is often stated too broadly.

“Once on demurrage, always on demurrage” is not an absolute rule that makes every minute payable regardless of the charterparty, the cause of delay or the owner’s own conduct.

The actual result depends on the charterparty. An exception may expressly apply to demurrage. Delay caused by owners may produce a different result. A vessel may become unavailable to charterers. Specific rider clauses can interrupt or modify the demurrage regime.

Understanding the rule therefore requires more than memorising a shipping maxim. It requires understanding the transition from laytime to demurrage and identifying exactly which contractual protections survive that transition.

Quick answer: Once laytime expires, ordinary laytime exceptions generally cease to apply and demurrage continues running. However, the charterparty may expressly provide otherwise, and periods caused by owners’ fault or circumstances for which owners are responsible can require separate analysis. The safest rule is therefore: once on demurrage, time normally continues unless the contract or a recognised legal principle stops it.

What Does “Once on Demurrage, Always on Demurrage” Mean?

The expression describes the change that normally takes place once the charterer’s agreed laytime has been exhausted.

During laytime, the charterparty determines which periods count and which periods are excepted.

Depending on the fixture, laytime might stop because of:

• Sundays;
• holidays;
• bad weather;
• strikes;
• specified breakdowns;
• certain port interruptions; or
• other expressly agreed exceptions.

Once the full allowed laytime has been consumed, however, the vessel moves into demurrage.

BIMCO’s Laytime Definitions for Charter Parties 2013 treat demurrage as the agreed amount payable to owners for qualifying vessel delay after laytime has expired and specifically state that ordinary laytime exceptions do not apply to demurrage unless the charterparty says otherwise.

This produces the familiar commercial shorthand:

Once on demurrage, always on demurrage.

But a more accurate operational version would be:

Once laytime expires, ordinary laytime exceptions generally no longer interrupt time unless the charterparty expressly extends them to demurrage or another recognised reason prevents demurrage from running.

Why Does the Rule Exist?

Laytime is the amount of time contractually allocated to charterers for loading or discharging.

Imagine that charterers are allowed five weather working days to load a vessel.

During those five days, bad weather may stop time from counting because the parties specifically agreed to measure the allowed period on a weather-working basis.

But once those five contractual days have been completely consumed, charterers have used their entire agreed allowance.

The commercial position has changed.

The vessel is now being detained beyond the period for which owners agreed to make her available without additional payment.

The demurrage rate becomes the contractual financial consequence of that delay.

If every laytime exception continued automatically after laytime expired, the charterer could potentially receive the same protection indefinitely even though the agreed time allowance had already been exhausted.

The traditional rule prevents that result unless the parties specifically agree otherwise.

What Changes When Laytime Expires?

Issue	During Laytime	After Demurrage Starts
Time status	Charterer’s contractual allowance remains	Allowed laytime has been exhausted
Payment	No additional payment for permitted laytime itself	Agreed demurrage rate may run
Weather exceptions	May stop time under WWD wording	Normally no longer stop time unless expressly applicable
SHEX	May exclude Sundays and holidays	Normally does not interrupt demurrage
Other exceptions	Apply according to charterparty	Must be checked to see whether they expressly extend to demurrage
Main commercial question	How much laytime remains?	How long does demurrage continue?

This transition is one of the most important points in any laytime and demurrage calculation.

Why Laytime Exceptions Normally Stop Applying on Demurrage

Consider a fixture that says:

“5 Weather Working Days, Sundays and Holidays Excluded.”

This defines the charterer’s free contractual time.

While the five days are still being consumed:

• qualifying bad weather may stop time;
• Sundays may be excluded;
• holidays may be excluded.

But if the vessel enters demurrage on Friday afternoon, those exceptions do not automatically continue simply because the same weather, Sunday or holiday occurs after Friday.

BIMCO’s approach is explicit: demurrage is not subject to laytime exceptions unless the charterparty specifically provides that those exceptions also apply during demurrage.

The practical question therefore changes from:

“Would this event have stopped laytime?”

to:

“Does this event also stop demurrage under this charterparty?”

Those are not the same question.

Example: Bad Weather After Laytime Expires

Assume the fictional bulk carrier M/V Tide Horizon has the following fixture:

Term	Agreed position
Allowed laytime	72 weather working hours
Demurrage	USD 24,000/day pro rata
Laytime expires	Tuesday 12:00
Rain stops loading	Tuesday 18:00–Wednesday 06:00
Loading completes	Wednesday 18:00

If the rain occurred before laytime expired and the weather-working-day wording applied, the relevant period might not have counted as laytime.

But here the vessel was already on demurrage.

If the charterparty does not expressly extend the weather exception to demurrage, the rain period normally continues counting.

Total demurrage period:

Tuesday 12:00 → Wednesday 18:00 = 30 hours

Daily demurrage rate:

USD 24,000

Hourly equivalent:

USD 24,000 ÷ 24 = USD 1,000/hour

Demurrage:

30 × USD 1,000 = USD 30,000

The 12 hours of rain are not automatically deducted merely because rain would previously have interrupted laytime.

Example: SHEX Before and After Demurrage

Now assume:

• Laytime terms: SHEX
• Laytime expires: Saturday 18:00
• Sunday is an excluded day during laytime
• Cargo operations finish: Monday 06:00

If Sunday occurred while laytime remained available, the SHEX provision could exclude the relevant Sunday period according to the charterparty.

But once demurrage begins at 18:00 Saturday, Sunday does not automatically become free time.

Unless the charterparty provides otherwise:

Saturday 18:00 → Monday 06:00 = 36 hours on demurrage.

At USD 20,000/day:

36 ÷ 24 = 1.5 days

1.5 × USD 20,000 = USD 30,000 demurrage

This example illustrates why the phrase “once on demurrage, always on demurrage” has major practical importance.

But “Once on Demurrage, Always on Demurrage” Is Not Absolute

The phrase is useful shorthand, but it should never replace the charterparty analysis.

There are two particularly important reasons why demurrage may not simply run uninterrupted:

1. The charterparty itself expressly provides that a particular exception applies to demurrage.
2. The relevant loss of time is attributable to owners or to circumstances for which owners bear responsibility.

Other specialised contractual provisions may also modify, suspend or reduce the demurrage regime.

The correct professional question is therefore not:

“The vessel is on demurrage, so does absolutely every minute count?”

It is:

“What does the charterparty say applies after laytime expires, and who is responsible for the specific time lost?”

Exception 1: The Charterparty Expressly Applies an Exception to Demurrage

The first exception is the clearest.

Parties are free to negotiate wording that applies not only during laytime but also during demurrage.

Consider these two hypothetical clauses.

Clause A

“Time lost due to strikes shall not count as laytime.”

This clearly addresses laytime.

It does not necessarily say that strike time stops once the vessel is already on demurrage.

Clause B

“Time lost due to strikes shall not count as laytime or time on demurrage.”

This wording is fundamentally different.

It expressly addresses the post-laytime period.

The phrase “once on demurrage, always on demurrage” therefore cannot be used to erase wording that the parties specifically negotiated to apply during demurrage.

Contract first, maxim second.

That is the safest way to analyse any demurrage exception.

Exception 2: Delay Caused by Owners

Another important limitation concerns delay caused by owners themselves.

Demurrage is designed to address charterers’ failure to complete cargo operations within the contractual time allocation.

It does not give owners an unrestricted right to create additional delay themselves and then charge charterers for every resulting hour.

Examples requiring careful analysis may include:

• ship machinery breakdown;
• failure of cargo gear for which owners are responsible;
• unready cargo holds;
• tank contamination attributable to the vessel;
• crew-related operational failure;
• owners withdrawing the vessel from charterers’ use;
• an owner-ordered operation performed solely for owners’ purposes; or
• another owner default that actually causes loss of cargo-operating time.

Whether time is deductible depends on the contract and causation.

The fact that an owner-side problem exists somewhere in the factual background does not automatically mean every subsequent hour stops counting.

The key issue is whether that matter actually caused the relevant delay and whether the charterparty allocates that risk to owners.

The Agios Dimitrios: Why the Maxim Has Limits

A useful practical illustration is discussed by Steamship Mutual in “Once On Demurrage, Always On Demurrage?”.

The vessel was carrying bulk cargo under an amended GENCON charterparty.

NOR had been accepted and loading began.

Laytime later expired, placing the vessel on demurrage.

The following day, however, it was discovered that the cargo holds still contained significant residues from the previous cargo.

Loading stopped.

The vessel had to leave the berth and undergo further cleaning before cargo operations could resume.

Owners argued that because the vessel had already entered demurrage, the demurrage clock should continue throughout the cleaning period.

But the charterparty contained wording addressing time lost because of crew or vessel mechanical failure, and the failure to prepare the holds properly was relevant to the time loss.

The result illustrates a crucial point:

The maxim cannot override express contractual wording dealing with deductions from demurrage.

It also demonstrates why operators should never stop reading the charterparty as soon as they determine that laytime has expired.

Owner Fault: Causation Still Matters

Suppose a vessel is already on demurrage when a main-deck crane breaks down.

At first glance, charterers may argue:

“Owner’s equipment failed. Stop demurrage.”

But the next question is:

Did the failure actually delay cargo operations?

If shore cranes were performing the entire operation and vessel equipment was not required, the breakdown may cause no actual loss of cargo-operating time.

Conversely, if the vessel’s crane was contractually required and loading could not continue without it, the causal position is very different.

Likewise, an owner-related event occurring at the same time as an independent charterer-side delay does not automatically determine the result.

A professional time-sheet analysis therefore separates:

Event → contractual responsibility → actual time lost → effect on demurrage.

What About Force Majeure, Strikes, Weather or Port Closure?

These events are often misunderstood after laytime expires.

Bad weather

If weather is an exception to laytime, it does not automatically mean weather stops demurrage.

The demurrage wording must be checked separately.

Strike

A strike clause may interrupt laytime but not necessarily demurrage.

If the clause expressly says that strike time is excluded from laytime and demurrage, the result may be different.

Port closure

A port closure occurring while the vessel is already on demurrage does not automatically stop the clock merely because neither party caused the closure.

The charterparty must allocate the risk.

Force majeure

The words “force majeure” should never be treated as a universal automatic defence to demurrage.

Voyage charterparties operate through their specific contractual wording. The relevant clause must be examined to determine whether the event is covered and whether its protection extends to demurrage.

This point has practical importance during major port disruptions. Steamship Mutual highlighted the same general issue when discussing delays following the Tianjin explosions: a vessel already on demurrage could continue accruing demurrage despite the subsequent event, depending on the applicable exceptions wording. See Steamship Mutual’s shipping issues guidance.

Full Worked Example: Laytime, Weather and Demurrage

Consider the fictional M/V Tide Pioneer.

Fixture item	Term
Cargo	60,000 MT bulk cargo
Laytime	72 weather working hours
Demurrage rate	USD 18,000/day pro rata
Laytime commences	Monday 08:00
Laytime expires	Thursday 20:00 after applicable laytime interruptions
Cargo completes	Saturday 08:00

Now suppose:

• Thursday 23:00–Friday 05:00: heavy rain stops loading;
• Friday 14:00–18:00: another rain stoppage;
• no clause specifically applies weather exceptions to demurrage.

Total time from laytime expiry to completion:

Thursday 20:00 → Saturday 08:00 = 36 hours

Total rain during that period:

10 hours

A common incorrect calculation would be:

36 − 10 = 26 demurrage hours.

But once the vessel is already on demurrage, the previous weather exception does not automatically continue.

The ordinary calculation is therefore:

36 demurrage hours.

Convert to days:

36 ÷ 24 = 1.5 days

Apply the rate:

1.5 × USD 18,000 = USD 27,000

Demurrage due: USD 27,000

The ten hours of rain still form part of the calculation because the fixture does not extend the weather exception into demurrage.

Now Change One Sentence in the Charterparty

Assume the same voyage, but the rider clause states:

“Time actually lost due to adverse weather shall not count as laytime or demurrage.”

Now the 10 rain hours may become deductible according to that wording.

Demurrage time:

36 − 10 = 26 hours

Convert:

26 ÷ 24 = 1.0833 days

Demurrage:

1.0833 × USD 18,000 ≈ USD 19,500

Compare the results:

Contract wording	Demurrage
Weather exception applies only to laytime	USD 27,000
Weather exception expressly applies to laytime and demurrage	Approx. USD 19,500

Difference: USD 7,500.

Nothing changed operationally.

The vessel experienced exactly the same weather.

The difference comes entirely from the contractual wording.

When Can the Demurrage Clock Stop?

There is no universal list that can be applied without reading the charterparty, but situations requiring careful analysis include:

Express demurrage exceptions

The contract may specifically state that particular periods do not count while the vessel is on demurrage.

Owner-caused delay

If owners prevent or materially delay cargo operations through their own default, demurrage may be interrupted depending on the circumstances and wording.

Vessel unavailable to charterers

If charterers cannot use the vessel for cargo operations because owners have withdrawn the ship from their effective disposal, the period requires separate consideration.

Specified mechanical failure

Some charterparties contain clauses expressly deducting time lost through vessel or cargo-equipment breakdown, including while on demurrage.

Contractual strike or force-majeure provisions

If the relevant provision expressly extends beyond laytime, it may modify the demurrage calculation.

Cargo operations complete

Demurrage ordinarily relates to the relevant delay in completing the charterer’s cargo operation. Determining the exact endpoint can itself depend on the charterparty and port facts.

“Always on Demurrage” Does Not Mean “Forever”

The word “always” makes the maxim memorable, but it can also make it misleading.

It does not mean that an owner receives an unlimited stream of demurrage regardless of contractual performance or whether the underlying obligations can still be performed.

The phrase primarily explains what happens to laytime exceptions after laytime expires.

It should not be transformed into a universal rule governing every possible future event.

This distinction matters particularly when comparing ordinary voyage-charter demurrage with other uses of the word demurrage, such as container detention or container demurrage regimes, which can involve different contractual structures.

Demurrage and Additional Damages: The Eternal Bliss

A separate but important question is what demurrage actually compensates once charterers fail to complete cargo operations within laytime.

The English Court of Appeal addressed this in The Eternal Bliss.

The voyage involved soybeans that remained aboard during a substantial discharge delay. Owners later faced a cargo-deterioration claim and sought recovery beyond the contractual demurrage already payable.

The Court of Appeal concluded that, where the only breach is the charterer’s failure to complete cargo operations within laytime, demurrage ordinarily liquidates the damages arising from that breach unless the charterparty indicates otherwise.

For detailed legal analysis, see Quadrant Chambers’ analysis of the Court of Appeal decision in The Eternal Bliss.

This is a different issue from whether demurrage time itself continues to count, but it reinforces a broader point:

Demurrage is a contractual risk-allocation mechanism, not simply a stopwatch multiplied by a daily rate.

Why the Statement of Facts Matters Once Demurrage Starts

When a vessel is on demurrage, operators sometimes become less concerned about recording individual interruptions because “all time counts anyway.”

That is dangerous.

The Statement of Facts remains critical because an interruption may later be alleged to:

• fall within an express demurrage exception;
• result from owner fault;
• result from vessel breakdown;
• have been caused by terminal or charterer operations;
• fall outside the relevant cargo operation;
• be unrelated to the vessel’s detention; or
• support a completely separate contractual argument.

The SOF should therefore continue recording events accurately even after laytime has expired.

Important entries can include:

• cargo stopped;
• cargo resumed;
• rain started and stopped;
• shore equipment breakdown;
• ship equipment breakdown;
• hatch opening and closing;
• shifting;
• berth ordered vacant;
• vessel moved to anchorage;
• hold cleaning;
• survey commenced and completed;
• cargo documents completed; and
• loading or discharge completed.

When a six-figure demurrage claim is disputed months later, a precise contemporaneous chronology can become more valuable than anyone expected during the port call.

Demurrage vs Despatch

The same laytime calculation can end in two opposite financial outcomes.

If charterers exceed the allowed time:

→ Demurrage

If charterers finish early and the charterparty provides for payment:

→ Despatch

	Demurrage	Despatch
Time position	Laytime exceeded	Laytime saved
Typical payer	Charterer	Owner
Typical recipient	Owner	Charterer
Key calculation issue	Which time continues after laytime expires?	ATS vs AWTS and qualifying time saved

Together, demurrage and despatch complete the financial side of the laytime calculation.

Common “Once on Demurrage” Mistakes

1. Deducting every rain stoppage

A weather exception that applies during laytime does not automatically continue after laytime expires.

2. Excluding Sundays because the fixture is SHEX

SHEX normally defines the laytime allowance. It does not necessarily create free Sundays while the vessel is already on demurrage.

3. Believing absolutely nothing can stop demurrage

Express charterparty wording or owner-caused delay can change the result.

4. Ignoring rider clauses

A printed form may state one position while a negotiated rider expressly extends an exception to demurrage.

5. Assuming force majeure automatically stops demurrage

The relevant contractual wording must be analysed.

6. Deducting an owner-side event without proving actual time loss

The existence of a vessel defect does not necessarily establish that the defect caused the disputed delay.

7. Stopping detailed SOF entries after laytime expires

The factual record remains essential because the cause of delay can still matter.

8. Calculating demurrage before calculating laytime correctly

You cannot know when demurrage begins until the valid laytime calculation has been completed.

9. Using arrival time as the automatic starting point

Laytime normally depends on the complete NOR and commencement machinery, not simply physical arrival.

10. Treating the maxim as if it were the charterparty

The actual contract always comes first.

Practical Demurrage Checklist for Operators

Step 1 — Establish valid NOR

• Was the vessel an arrived ship?
• Was she physically ready?
• Was she legally ready?
• Was NOR served to the correct party?
• Were permitted tendering hours satisfied?
• Did WIBON, WIPON, WIFPON or WCCON affect the position?

Step 2 — Establish laytime commencement

• What notice period applies?
• Did laytime begin immediately or after a stated period?
• Were weekends or holidays relevant?
• Was early cargo commencement relevant under the fixture?

Step 3 — Calculate allowed laytime

• Fixed hours or days?
• Cargo-rate calculation?
• Separate or reversible laytime?
• Loading and discharge allowances?

Step 4 — Apply laytime exceptions

• Weather?
• SHEX?
• Holidays?
• Strikes?
• Breakdowns?
• Shifting?
• Other rider-clause exceptions?

Step 5 — Identify exact laytime expiry

This timestamp is critical.

Before it:

laytime rules apply.

After it:

demurrage rules apply.

Step 6 — Re-read every exception

Do not simply continue using the laytime calculation rules.

Ask:

Does this clause expressly apply while on demurrage?

Step 7 — Check owner-side delays

• Ship breakdown?
• Cargo gear failure?
• Hold/tank problem?
• Crew issue?
• Owner-requested interruption?

Then ask whether it actually caused the claimed time loss.

Step 8 — Calculate demurrage pro rata

For a USD 24,000/day rate:

Hourly rate = USD 1,000

For 43 hours on demurrage:

43 × USD 1,000 = USD 43,000

Step 9 — Match calculation to evidence

Cross-check:

• Charterparty;
• fixture recap;
• rider clauses;
• NOR;
• Statement of Facts;
• time sheet;
• weather reports;
• letters of protest;
• terminal reports; and
• relevant correspondence.

Where “Once on Demurrage” Fits in the Chartering Sequence

The principle makes most sense when placed within the complete voyage-chartering chain:

Charterparty agreed
↓
Laycan fixed
↓
Vessel arrives
↓
WIBON / WIPON / WIFPON / WCCON assessed where relevant
↓
NOR tendered
↓
Laytime commences
↓
Laytime exceptions apply
↓
Allowed laytime expires
↓
VESSEL ENTERS DEMURRAGE
↓
Ordinary laytime exceptions cease unless specifically preserved
↓
Express demurrage exceptions / owner fault checked
↓
Cargo operations complete
↓
SOF and time sheet finalised
↓
Demurrage amount calculated

This is the point of the maxim.

It marks a change in the contractual time regime.

Continue the Tide Signal Chartering Series

• Charterparty in Shipping — understand the contractual framework behind the fixture.
• Laycan in Shipping — laydays, cancelling date, extensions and late arrival.
• Notice of Readiness in Shipping — when NOR may be valid and when laytime starts.
• WIBON, WIPON, WIFPON & WCCON — geographical and formal readiness for NOR.
• Laytime and Demurrage in Shipping — the complete calculation framework.
• Statement of Facts in Shipping — why every operational timestamp matters.
• Despatch in Shipping — calculation of time saved, ATS and AWTS.

Once on Demurrage, Always on Demurrage: Frequently Asked Questions

What does “once on demurrage, always on demurrage” mean?

It means that once the permitted laytime has expired and the vessel enters demurrage, exceptions that applied only to laytime generally cease to stop the clock. Demurrage normally continues unless the charterparty expressly provides otherwise or another recognised reason interrupts it.

Does bad weather stop demurrage?

Not automatically. A weather exception that suspends laytime will not normally suspend demurrage unless the charterparty extends the exception to demurrage.

Does SHEX apply when a vessel is on demurrage?

Not automatically. A Sunday or holiday excluded from laytime can still count as time on demurrage unless the charterparty specifically preserves the exception.

Does SHINC matter once a vessel is on demurrage?

SHINC means Sundays and Holidays Included during the laytime regime. Once the vessel is already on demurrage, all time will generally count in any event, subject to the charterparty’s demurrage provisions.

Can demurrage stop because of a vessel breakdown?

Potentially. The result depends on the charterparty, the nature of the breakdown and whether it actually causes relevant time loss. Some clauses expressly deduct owner-side or vessel-breakdown time from demurrage.

Can owner’s fault stop demurrage?

Owner-caused delay can require demurrage to be suspended or adjusted depending on causation and the contractual allocation of risk. Owners cannot automatically charge charterers for delay that owners themselves are responsible for creating.

Does force majeure automatically stop demurrage?

No. The presence of a force-majeure event does not itself establish that demurrage stops. The applicable charterparty wording must be examined to determine whether the event is covered and whether the provision applies after laytime expires.

Do strikes stop demurrage?

Only if the relevant contractual provision applies to demurrage or another applicable legal basis produces that result. A strike exception referring only to laytime does not necessarily stop time after demurrage begins.

When exactly does a vessel go on demurrage?

The vessel enters demurrage when the total allowed laytime has been exhausted, after applying the correct commencement provisions and all applicable laytime exceptions.

Does demurrage begin when the vessel arrives?

No. Vessel arrival is normally only one part of the process. NOR, readiness, contractual arrival position, notice periods and the actual laytime allowance must first be analysed.

Can a vessel go on demurrage while still at anchorage?

Yes, depending on the charterparty. If a valid NOR has been tendered, laytime has commenced and the permitted laytime expires while the vessel is still waiting, demurrage may begin before berthing.

Does demurrage run 24 hours per day?

Once demurrage starts, time generally runs continuously, subject to express contractual provisions and recognised deductions. The daily rate is normally applied pro rata to partial days where the charterparty provides accordingly.

What is the difference between laytime and demurrage?

Laytime is the contractually allowed period during which owners make the vessel available for cargo operations without additional payment beyond freight. Demurrage is the agreed financial consequence of qualifying delay after that permitted laytime has expired.

What is the difference between demurrage and despatch?

Demurrage generally arises when permitted laytime is exceeded. Despatch may arise when cargo operations finish before permitted laytime expires and the charterparty provides for a payment to charterers.

What documents are needed for a demurrage calculation?

The fixture recap, charterparty, rider clauses, NOR, Statement of Facts and time sheet are fundamental. Weather records, port logs, terminal reports, correspondence and letters of protest may also be important where individual interruptions are disputed.

Is “once on demurrage, always on demurrage” written into every charterparty?

No. It is a well-known shorthand for a general demurrage principle, not wording that must literally appear in every charterparty. The actual contract remains decisive.

Final View

“Once on demurrage, always on demurrage” is powerful because it identifies the moment when the commercial time regime changes.

Before laytime expires, charterers are still using an agreed time allowance and can benefit from the exceptions contained in that allowance.

After laytime expires, that contractual allowance has gone.

The vessel is being detained beyond the permitted period, and ordinary laytime exceptions generally no longer protect charterers.

But the word “always” should never tempt an operator into ignoring the charterparty.

Demurrage can still be affected by:

• express provisions applying exceptions during demurrage;
• owner-caused delay;
• vessel or crew default;
• specific breakdown provisions;
• special strike or force-majeure wording;
• the actual cause of the delay; and
• other negotiated rider clauses.

The correct analysis is therefore:

First calculate when laytime expires. Then identify every hour after that point. Then ask whether the charterparty or owner responsibility provides a specific reason why any of those hours should not count as demurrage.

That method is safer than applying the slogan mechanically.

Tide Signal view: “Once on demurrage, always on demurrage” should be treated as the starting presumption after laytime expires — not the end of the analysis. The decisive question is whether the event that stopped cargo operations was merely a laytime exception that has now fallen away, or a contractual or owner-side event capable of interrupting demurrage itself.

Authoritative Sources and Further Reading

• BIMCO — Laytime Definitions for Charter Parties 2013 — industry definitions of laytime, demurrage, despatch and related voyage-charter terminology.
• BIMCO — Laytime Definitions 2013 PDF — direct reference including the principle that demurrage is not subject to laytime exceptions unless specifically stated in the charterparty.
• Steamship Mutual — Once On Demurrage, Always On Demurrage? — practical discussion of the principle, owner responsibility and the Agios Dimitrios.
• Steamship Mutual — Tianjin Shipping Issues — useful illustration of how subsequent external events interact with a vessel already on demurrage.
• Quadrant Chambers — The Eternal Bliss — analysis of the Court of Appeal’s treatment of demurrage as the remedy for consequences of failure to complete cargo operations within laytime where no separate breach exists.

This article provides a general educational, operational and commercial explanation of demurrage under voyage charterparties. Actual rights and liabilities depend on the complete charterparty, fixture recap, rider clauses, governing law and individual voyage facts. It does not constitute legal advice.