Off-Hire and Performance Claims in Time Charters

Off-hire and performance claims together govern the core financial risk allocation in a time charter party. Off-hire suspends hire payment when the vessel can’t perform because of a cause on the owner’s side of the risk ledger. Performance claims produce damages when the vessel, though operating, fails to achieve the speed or fuel consumption the owner warranted. Both mechanisms are dense in English-law authority and in BIMCO standard clauses, and both are routinely the subject of London Maritime Arbitrators Association (LMAA) arbitrations running into six or seven figures. Use the off-hire deduction calculator to quantify a specific deduction under NYPE Clause 17, and the charter hire off calculator for the broader NYPE / Baltime off-hire credit computation.

Off-hire: the contractual mechanism

Off-hire is not a common-law remedy. English law, which governs the great majority of international time charters by express choice, does not recognize a general right to suspend hire payment absent a contractual provision. The charterer’s remedy for a vessel that can’t earn is entirely a creature of the off-hire clause, and the scope of that clause determines everything: which events trigger it, how long it runs, how the deduction is measured, and whether bunker costs during the period fall to the owner.

The standard NYPE time charter in its 1946 edition (Clause 15) and its 1993 revision (Clause 17) both adopt a net loss of time formulation. NYPE 2015 Clause 17, the current authoritative text, reads in relevant part that hire is to cease for any time lost in consequence of the vessel being unable “to perform the service immediately required” on account of:

• deficiency of men, stores, or provisions
• breakdown of or damage to hull, machinery, or equipment
• drydocking for the purpose of examination or painting of bottom
• detention by average accidents to ship or cargo
• any other similar cause preventing the full working of the vessel

The qualifier “net loss of time” is the critical operative phrase. The charterer doesn’t get a deduction for the whole period of an off-hire event; it gets a deduction equal to the time the vessel was actually ineffective. If an engine fails on a voyage from Rotterdam to Singapore and the crew manages to continue at reduced speed, losing four hours against a notional schedule, the deduction is four hours, not the full transit time. The 1946 / 1993 NYPE formulation is identical in structure on this point. Baltime, the BIMCO-sponsored alternative time charter form, uses a period off-hire approach (see below).

Net loss of time versus period off-hire

The distinction between the two clause types has major financial consequences.

A net-loss-of-time clause (NYPE 2015 Clause 17; Shelltime 4 Clause 21(a)) deducts only the time actually lost. If the vessel drydocks for 15 days but its drydocking coincides with a port delay of 12 days that would have occurred anyway, the off-hire period for the drydocking may be only the three non-overlapping days, because the charterer lost only three days of commercial use it would otherwise have enjoyed. The parties argue about causation and counterfactual loss, and arbitrators apply the “net” standard strictly.

A period off-hire clause (Baltime Clause 11; Shelltime 4 Clause 21(b) as an option) runs from the moment the event occurs until the vessel is fully restored, regardless of partial service during the interval. The owner can’t argue that the vessel kept trading at reduced capacity; the full period is off-hire. This is the more charterer-friendly formulation and owners resist it in negotiation.

Most bespoke charterparty amendments for tanker charters insert intermediate provisions: a period clause for major mechanical events (main engine failure) and a net-loss-of-time clause for partial operational impairments (one generator of three failing). Identifying which sub-clause applies to a given breakdown is itself a recurring source of dispute.

Events that trigger off-hire

NYPE 2015 Clause 17 lists the triggering causes non-exhaustively. The cases that reach arbitration are almost never about main engine seizures, which are clear. They’re about the edge conditions: how deficient is “deficiency of men”? Does a single absent chief engineer suffice? The LMAA body of awards treats the threshold as functional incapacity, not mere substandard manning; a single officer absent doesn’t take the vessel off-hire unless the absence creates a specific operational limitation.

Machinery breakdown is the most frequent trigger. The event must prevent full working, not merely slow it. A main engine running at 85% of rated power because of fuel-injection fouling may or may not prevent “full working” depending on whether the charterer instructed a slower speed on that leg. Arbitrators examine what service was “immediately required” at the time, a standard that varies with voyage instructions.

Deficiency of stores is rarer in modern practice but surfaced prominently in bunker-shortage periods. If the owner runs the vessel to the point where bunker stocks fall below safe operational margins and the vessel diverts to bunker, the bunkering deviation may be off-hire.

Drydocking is expressly off-hire under NYPE 2015 Clause 17. The clause requires the owner to give reasonable notice and the charterer to approve the timing, though approval can’t be withheld unreasonably for a class-mandated survey. Unscheduled drydocking for damage repair is also off-hire, and its duration, plus any mobilization and waiting time, falls to the owner.

Detention by port state control (PSC) is the most litigation-dense trigger in modern practice. The NYPE 2015 wording covers “detention by average accidents to ship or cargo” and “any other similar cause preventing full working.” Whether a PSC detention fits either limb depends on what caused the detention: class deficiencies traceable to owner maintenance failures are on-hire lost time for the charterer but the courts have held some PSC detentions off-hire when they arise from defects in the ship’s condition that predate the charter. Charterer-caused detentions (cargo prohibition orders, charterer’s agents’ failures, charterer-ordered port calls for re-inspection) are generally at the charterer’s risk and keep the vessel on-hire.

Crew strikes sit explicitly in the NYPE 2015 list. Owner-side industrial disputes (collective bargaining stoppages covering the vessel’s flag-state crew pool) take the vessel off-hire. Charterer-organized boycotts or cargo-related industrial action at ports are not owner-side events and remain on-hire.

The NYPE 2015 six-hour threshold

NYPE 2015 Clause 17 introduces a six-hour deductible: no off-hire is claimable for any individual period of off-hire of less than six consecutive hours. This threshold was not in the 1946 or 1993 forms and represents a significant owner-favorable shift. The intent is to filter out minor engine-room incidents and transient deficiencies that historically generated small but administratively burdensome deductions. Charterers negotiating NYPE 2015 forms frequently push back on this threshold or substitute a 12-hour trigger with a 24-hour catch-up if multiple short events aggregate over a voyage.

Use the grace-period deductible calculator to model the effect of a six-hour threshold on a particular incident history.

Calculating the off-hire deduction

The formula above captures the core NYPE Clause 17 deduction: hire rate multiplied by the net hours lost, divided by 24 to convert to a daily-rate basis, plus the fuel cost during the off-hire period that the owner must absorb. In practice, the calculation requires several inputs that are themselves disputed.

When does off-hire start? The NYPE forms say “time lost,” not “time when the breakdown was reported.” If a defect develops gradually, the off-hire period begins when the deficiency crosses the threshold of preventing full working, which is a factual question the arbitrators resolve on the evidence. Noon reports, engine room logs, and chief engineer’s statements are the primary documents; in major disputes, expert engineers review the logs to reconstruct the fault timeline.

When does off-hire end? The vessel comes back on-hire when it’s restored to full operational capability. A vessel that completes repairs and then waits at anchor for a berth is on-hire once repairs are done; the berth-waiting time is the charterer’s operational risk. A vessel that deviates to a repair port and then repositions to the voyage route may have off-hire running through the deviation, but the repositioning voyage is generally on-hire once the vessel is technically restored.

Bunker cost allocation. The NYPE off-hire clause doesn’t automatically require the owner to pay for all bunkers consumed during off-hire. It requires the charterer not to pay hire. The bunkers question is governed by the charter party’s bunker clause, which typically imposes on the owner the cost of bunkers consumed during off-hire caused by owner-side events. In practice, a vessel on-hire consumes charterer’s bunkers; during off-hire, the owner absorbs the cost of bunkers consumed by the vessel’s own systems (hotel load, crew services) but not necessarily the propulsion fuel, because the vessel isn’t moving.

Speed and consumption warranties: structure and scope

Every serious time charter party contains a performance warranty. The standard form is a combined speed-and-consumption clause: the owner warrants that the vessel will achieve a stated speed consuming not more than a stated quantity of fuel, in specified conditions.

NYPE 2015 Clause 24 is titled “Speed and Consumption” and provides that the owner warrants the vessel’s performance on the basis of the description appended to the charter, which in practice is the vessel’s description schedule. That schedule states, for each condition (laden, ballast, at a specified speed), the warranted consumption of main engine fuel and auxiliary fuel, the type of fuel, and the weather conditions under which the warranty applies. A typical bulker warranty might read:

“Speed about 14.0 knots, main engine consumption about 32 metric tonnes per day on HFO 380 cSt, auxiliary consumption about 3 metric tonnes per day on MGO, laden in good weather conditions not exceeding Beaufort Force 4 and Douglas Sea State 3, no adverse current.”

Each element of that clause is a source of dispute.

The “about” margin

The word “about” preceding both the speed and the consumption figure introduces a margin of tolerance. English law has settled at plus or minus 0.5 knots for speed and a proportionate margin for consumption, though the cases aren’t fully harmonized and the BIMCO Speed and Consumption Clause 2023 codifies a 0.5-knot speed margin explicitly. Where the charter says “about,” an owner whose vessel achieves 13.6 knots when the warranty is 14.0 knots is not necessarily in breach; 13.5 knots (warranted minus 0.5) is the floor. Below 13.5 knots on the good-weather sample, a breach arises.

Good weather: the Beaufort and Douglas conditions

Performance warranties apply only in conditions defined as good weather. The near-universal definition combines the Beaufort wind scale and the Douglas sea-state scale. Beaufort Force 4 means wind of 11 to 16 knots; it’s the threshold above which trade-wind chop begins to materially affect a laden bulker or tanker. Douglas Sea State 3 is “slight” to “moderate,” with significant wave heights of 0.5 to 1.25 metres.

Some charters add a wave-height condition (no waves above 1.5 metres) or a current condition (no adverse current exceeding 0.5 knots). The current condition is specifically contentious in route segments with known persistent currents, such as the Gulf Stream, the Agulhas Current off South Africa, and the Kuroshio Current in the western Pacific. Charterers claim adverse currents don’t count as weather-imposed; owners argue the warranty says “no adverse current” regardless of whether it’s weather-driven or oceanic. The BIMCO Speed and Consumption Clause 2023 addresses this by defining separately “sea conditions” and “current conditions,” tightening the threshold definition and reducing ambiguity.

“Clean bottom” and draught conditions

The speed warranty almost always includes a condition that the vessel is “on clean bottom.” Biofouling reduces speed and raises fuel consumption; a vessel with heavy barnacle growth performing at 12.5 knots against a 14.0-knot warranty isn’t necessarily in breach if the charterer authorized a long period without hull cleaning. The “clean bottom” condition doesn’t mean the hull was just cleaned; it means the fouling state is within the tolerance that a diligent owner maintaining the vessel under reasonable trading conditions would keep the hull. The date of the last antifouling paint application, the paint’s guaranteed fouling-release period, and the time since last hull clean are all relevant evidence in a performance claim that involves a fouling defense.

Draught is also a condition: the speed warranty typically applies at a specified draught (full-load laden draught or a standard ballast draught). A vessel loaded 15% heavier than the warranted draught can’t be held to the warranted speed; displacement affects resistance non-linearly, with a cubic relationship between speed and resistance for a given displacement.

Performance claims: calculation methodology

When a charterer concludes the vessel’s performance falls short of the warranty, it calculates a performance claim by working through the voyage data systematically.

Step 1: Identify good-weather observation periods

From the vessel’s noon reports and the weather routing service reports, the charterer’s expert extracts all periods where the conditions match the warranty definition. Periods where wind exceeded Beaufort 4 or sea state exceeded Douglas 3 are excluded. Periods under heavy swell (beam or following swell that doesn’t register on the wind scale but creates significant rolling and added resistance) are a contested exclusion. Anchoring periods, port maneuvering, and drydock time are excluded. What remains is the pool of “good-weather sea passages.”

The leading English case on good-weather sampling methodology is The Didymi [1988] 2 Lloyd’s Rep 108 (CA). The Court of Appeal confirmed that the performance warranty is tested by reference to a sufficient sample of good-weather observation periods, not by averaging across the whole voyage including bad weather. It also confirmed that the charterer doesn’t have to show each individual period of underperformance; it can average the good-weather observations across the charter to establish a systematic shortfall. Subsequent awards by LMAA tribunals have refined this into a “voyage-by-voyage or charter-period” election that charterers make at the outset of a claim.

Step 2: Calculate observed speed and consumption

Over the good-weather sample, the charterer’s analyst computes:

• Average observed speed (nautical miles sailed over time elapsed, not SOG from GPS, which includes current effects unless the warranty specifies otherwise)
• Average observed main engine fuel consumption (bunker log readings cross-checked against bunker delivery notes)
• Average auxiliary consumption (separate generator and boiler logs)

Any discrepancy between the deck log data and the weather routing service data is resolved in favor of the better-evidenced source, which is almost always the weather routing service (companies such as StormGeo, MeteoGroup, and Oceanweather). The weather routing service’s hindcast reconstruction of actual conditions at the vessel’s position is preferable to the vessel’s own visual observations, which are subjective and recorded only at noon.

Step 3: Convert shortfall to time lost and excess consumption

Time lost from a speed shortfall over a voyage:

where $D$ is the voyage distance in nautical miles, $v_\text{actual}$ is the observed average good-weather speed in knots, and $v_\text{warranted}$ is the warranted speed. If the warranty includes an “about” margin, the warranted speed for claim purposes is the warranty figure minus the margin (e.g., 14.0 minus 0.5 = 13.5 knots effective floor).

Excess fuel consumption per day:

where $c_\text{actual}$ and $c_\text{warranted}$ are the actual and warranted daily consumption rates in metric tonnes per day, and $t_\text{good}$ is the total good-weather sea-passage time in days.

Total claim value:

where $H$ is the daily hire rate and $P_\text{fuel}$ is the price per metric tonne of the relevant fuel grade at the time of over-consumption. Fuel price is typically taken from the Platts or Argus bunker price assessments for the relevant port and grade, on the date the excess was burned. Disputes arise over whether to use the price the charterer actually paid (commercial reality) or the published assessment (contractual neutrality). The BIMCO Speed and Consumption Clause 2023 opts for the date and port of delivery of the bunkers consumed.

Step 4: Counter-analysis and adjustments

The owner’s response to a performance claim typically attacks one or more steps. Common defenses include:

Current adjustment. If the voyage crossed a persistent ocean current, the owner argues that GPS-derived SOG reflects current assistance or adverse current, and the true through-water speed (the warranty measure) is different. Independent current data from the U.S. Navy HYCOM model or from the weather routing service’s drift calculations are used to adjust.

Draught variation. If the vessel was more deeply loaded than the warranty condition, the owner adjusts the warranted speed downward using the vessel’s speed-power curve for the actual draught. This requires the vessel’s model-test resistance data or an accepted empirical formula.

Hull fouling above baseline. The owner argues that fouling beyond what a diligent owner could prevent (e.g., the charterer ordered the vessel to a port where anti-fouling inspection was prohibited, or the charter duration exceeded the paint guarantee period) should excuse part of the shortfall. This defense is strong when corroborated by underwater inspection records and paint certification.

Fuel grade mismatch. If the charterer supplied a fuel of different viscosity or calorific value than the warranty fuel grade, the owner argues the performance comparison is invalid without a fuel-quality adjustment. This is tested against the bunker delivery notes and fuel sample analysis certificates.

Burden of proof

The allocation of the burden of proof in English performance claim arbitrations follows the scheme from The Gas Enterprise [1993] 2 Lloyd’s Rep 352: the charterer bears the initial burden of demonstrating a prima facie shortfall against the warranty in good-weather conditions. Once that prima facie case is established, the burden shifts to the owner to explain the shortfall by reference to factors outside the warranty (draught, fouling above baseline, current, fuel grade). If the owner can’t explain the full shortfall, the unexplained residual is treated as warranty breach.

The Ocean Virgo [2015] Lloyd’s Rep Plus 68 (LMAA award, upheld on appeal) further confirmed that the good-weather sampling methodology doesn’t require a minimum observation period to be statistically valid, but that the arbitrators will discount a sample that is too thin to be representative. In practice, a single 24-hour good-weather period is seldom sufficient; experienced charterers’ experts work with a minimum of 5-7 qualifying days of observation before asserting a claim.

Comparison of off-hire clause structures across standard forms

The “no custom weather threshold” row reflects a real drafting gap: none of the major forms defines Beaufort Force 4 or Douglas Sea State 3 in the charter party body; the definition appears only in the performance warranty schedule, if at all. The BIMCO Speed and Consumption Clause 2023 is the first BIMCO product to place the weather definition inside the operative clause text rather than leaving it to bespoke schedule language.

The BIMCO Speed and Consumption Clause 2023

BIMCO published the Speed and Consumption Clause for Time Charter Parties in 2023, replacing earlier versions from 2013. The clause addresses the deficiencies that generated the most LMAA disputes under the open-form warranties.

Key provisions:

Weather definition. Wind not exceeding Beaufort Force 4 and sea state not exceeding Douglas Sea State 3, with wave height not exceeding 1.5 metres and no adverse current exceeding 0.5 knots. The “about” margin for speed is stated as 0.5 knots and for consumption as 5%.

Qualifying observation periods. Periods of less than six hours are excluded from the good-weather sample. This provision reduces disputes over isolated weather windows.

Fuel over-consumption. The clause specifies that excess consumption is priced at the date and port of the last bunker delivery before consumption, using the invoice price. If the charterer supplied off-spec fuel, the clause contains an adjustment mechanism.

Charter-period aggregation. The claim is calculated on a full-charter basis, not voyage by voyage, unless the parties elect otherwise. This prevents a charterer from cherry-picking favorable voyages for claims while ignoring voyages where performance exceeded the warranty.

Submission period. Claims must be submitted within 90 days of redelivery or they’re time-barred. This provision codifies a practice that many one-off charter party additions had attempted but left poorly defined.

The BIMCO Slow Steaming Clause for Time Charter Parties 2013, still in wide use, addresses a different problem: when the charterer orders the vessel to reduce speed below the warranted figure for commercial or environmental reasons, the charter party needs to state explicitly how the performance warranty applies at the reduced speed. The clause provides a mechanism for the parties to agree a slow-steaming mode that modifies the warranted figures proportionally.

The CII and EEXI overlay on performance warranties

The IMO Carbon Intensity Indicator (CII) rating, mandatory from 1 January 2023 under MARPOL Annex VI Regulation 28 read with MEPC.338(76), introduced an operational constraint that interacts with traditional speed-and-consumption warranties in time charters.

Under CII, a vessel’s annual AER (Annual Efficiency Ratio) or cgDIST is reported to flag state and class, producing a rating from A to E. A D or E rating over consecutive years triggers a mandatory corrective action plan and, if uncorrected, potential flag-state restriction on trading. The BIMCO CII Operations Clause 2022 allocates this risk between owner and charterer.

The interaction with performance warranties is threefold.

First, a charterer instructing slow steaming to achieve a better CII rating (lower fuel burn = lower CO₂ per distance) changes the speed at which performance is tested. If the charter includes the BIMCO Slow Steaming Clause, this is managed. If it doesn’t, there’s ambiguity about whether the owner warranted performance at any speed or only at the charter-speed description.

Second, an owner who restricts the vessel’s speed by an Engine Power Limitation (EPL) or by ShaPoLi to meet the EEXI standard may find the vessel can no longer physically achieve the warranted charter speed. EEXI compliance was mandatory from 1 November 2022 under MEPC.328(76). Where a vessel’s EEXI-compliant limited MCR produces a sea-speed limitation below the charted warranty speed, the owner faces a conflict between the regulatory obligation and the contractual warranty. The BIMCO EEXI Transition Clause 2021 addresses this by allowing the owner to notify the charterer of a revised warranted speed reflecting the EPL, with a hire adjustment formula. Charters without this clause face a harder argument.

Third, the CII framework creates data-collection requirements (noon reports in a CII-compliant format) that overlap with the performance-claim documentation. Charterers in CII-compliant charters have access to more granular performance data than before, which strengthens their evidentiary position in speed and consumption claims.

For context on the regulatory architecture, see the related articles on BIMCO CII clauses, slow steaming and CII, and what is EEXI.

Weather routing evidence and independent voyage reconstruction

The single most contested factual question in a time charter performance claim is what the weather was. The vessel’s deck log records visual observations made by the officer of the watch at noon and sometimes at 0600 and 1800. These observations are made from the bridge, are subjective, and are entered in round Beaufort numbers (Force 4 or Force 5, not 4.2). Weather routing service hindcasts reconstruct the meteorological and oceanographic conditions at each recorded vessel position using numerical weather prediction model output and satellite altimetry for wave height.

The leading weather routing and performance analysis companies providing hindcast reports for claims purposes include StormGeo (formerly DTN), MeteoGroup, and Oceanweather. Their reports compare the vessel’s observed log data (position, speed, heading, engine revolutions per minute) against the reconstructed metocean conditions and identify, hour by hour, which periods qualify as good weather. For most LMAA arbitrations, the quality of the weather routing service’s hindcast is dispositive; tribunals rarely prefer the deck log’s visual Beaufort observation over a satellite-validated model reconstruction.

The interaction between weather routing services and performance monitoring tools has grown more sophisticated. Continuous engine monitoring systems, shaft-power meters (torsiometers), and vessel performance optimization (VPO) systems now record propeller shaft power, torque, and RPM continuously. This data, when combined with AIS-derived position and speed data and metocean models, allows a virtually continuous performance reconstruction rather than a noon-to-noon reconstruction. Charterers who specify continuous performance monitoring in the charter party have a stronger evidentiary base for claims than those relying on noon reports alone.

Off-hire and performance claims in practice: the claim lifecycle

Most time charter performance claims don’t proceed to arbitration. They’re settled at redelivery or in the months following, when the charterer presents a claim schedule and the parties negotiate a settlement figure. The pattern is:

1. During the charter, the charterer’s operations team flags voyages where performance seems short. Noon reports are reviewed against the warranted figures monthly.
2. At redelivery, the charterer submits a preliminary performance claim covering the full charter period.
3. The owner responds with a counter-analysis, typically disputing the good-weather selection and asserting fouling or current defenses.
4. The parties exchange expert reports. If the gap is large (over $500,000), each side retains a naval architect or marine engineering expert plus a weather routing service.
5. Settlement negotiations commence. Most charter disputes below $1 million settle without formal arbitration. Above$1 million, the probability of LMAA arbitration rises substantially.

Off-hire claims have a different lifecycle because the events are real-time. The charterer issues an off-hire notice when the event occurs; the owner disputes it or accepts it. The deduction appears in the next hire payment (or the charterer withholds from the payment and the owner disputes the withholding). Contested off-hire claims that aren’t settled at hire payment often accumulate across a charter and are consolidated into an LMAA claim at redelivery alongside the performance claim.

The hire payment context matters. Under English law, hire is payable in advance. A charterer who withholds hire for a disputed off-hire event risks the owner exercising a right to withdraw the vessel for non-payment, provided the charter party grants that right and the contractual prerequisites are satisfied. The charter withdrawal calculator models the financial exposure on a disputed withdrawal scenario. Charterers typically protect themselves by paying hire in full under reservation of rights and claiming restitution, rather than withholding.

Interaction with hull and machinery insurance and loss of hire cover

Off-hire events caused by machinery breakdown are the intersection of the off-hire clause and the hull and machinery (H&M) insurance policy. When a main engine failure causes off-hire, the owner typically has two potential recoveries: from the H&M insurer for the cost of repairs, and from a separate loss of hire (LOH) policy for the hire income lost during the repair period.

LOH policies cover the daily hire income (or a stipulated daily indemnity) for each day of off-hire exceeding the policy deductible, typically 14 days. The deductible is the critical parameter: a breakdown repaired in 10 days produces no LOH recovery, while a repair taking 30 days produces recovery for 16 days (30 minus 14). The policy typically excludes scheduled drydocking, dry-dock waiting time beyond a specified cap, and off-hire caused by charterer’s acts.

The relationship between the charter party off-hire clause and the LOH policy isn’t automatic. The LOH policy defines its own covered perils and its own deductible, which may not match the charter party’s off-hire trigger and duration. A PSC detention that is off-hire under the charter party may not be a covered peril under the LOH policy if the policy defines perils by reference to physical damage to the vessel. See the loss of hire insurance article for coverage structure detail.

Hull performance degradation from fouling also creates an intersection with the ISO 19030 hull performance standard, which provides a standardized methodology for measuring speed loss against a reference baseline. ISO 19030-2 defines the speed loss threshold (5% relative to the reference period) at which hull cleaning is triggered. In a charter party performance claim, an owner whose vessel’s fouling-related speed loss is within the ISO 19030 threshold has a stronger argument that the hull was in a clean-enough condition to hold the performance warranty.

Practical documentation and evidence management

The quality of the documentary evidence determines the outcome in most performance claim arbitrations. The key documents are:

Noon reports. Position, distance run since last noon, average speed, engine RPM, main engine fuel consumed, auxiliary fuel consumed, weather observed (wind force and direction, sea state, swell), and any off-hire events. These are the primary raw data for both performance claims and off-hire calculations. Masters and chief engineers who understand the evidentiary significance of noon reports maintain them more carefully; shipmanagers who install performance reporting software with automated noon report generation have better data quality.

Bunker delivery notes (BDNs). Under MARPOL Annex VI Regulation 18, every bunker delivery requires a BDN signed by the bunker barge master and the vessel’s chief engineer, stating the quantity, viscosity, sulfur content, and density of fuel delivered. The BDN is the primary evidence of bunker quantity received, from which consumption is calculated against the opening and closing ROB (remaining on board) figures.

Sea trials results. The vessel’s builder sea trials demonstrate the warranted performance under controlled conditions. For a performance claim, the sea trials data is the baseline against which fouling degradation is measured and the owner’s defense of “designed performance not achievable” is tested.

Classification society and class survey records. These establish the vessel’s maintenance status, defect history, and dry-docking record. A class survey conducted immediately before the charter, showing no condition items, strengthens the owner’s position that the vessel started the charter in warranted condition.

Engine room logs. Hour-by-hour records of main engine RPM, power output, fuel rack settings, exhaust temperatures, turbocharger performance, and cylinder pressures. The engine room log is the primary evidence for breakdown timing and, in a continuous monitoring environment, for performance reconstruction.

Limitations

Several limits on the framework described above deserve explicit statement.

The case law cited here (The Didymi, The Gas Enterprise, The Ocean Virgo) reflects English law and LMAA arbitration practice. Time charters governed by New York law and arbitrated before the Society of Maritime Arbitrators (SMA) follow similar principles but with differences in burden of proof allocation and in the treatment of expert evidence. Charters governed by Singaporean law (SCMA arbitration) increasingly reference English authority but aren’t bound by it.

The CII and EEXI overlay on performance warranties is a rapidly developing area. The BIMCO clauses published to date address the principal scenarios, but cases involving EPL-limited vessels whose warranted speed exceeded their regulatory maximum power output haven’t yet produced a body of LMAA authority. Owners and charterers entering CII-era charters should treat the relevant BIMCO clauses as minimum safeguards rather than complete allocations.

Good-weather sampling methodology is not fixed by any statute or IMO instrument. The Beaufort 4 / Douglas 3 threshold is industry practice, not law. A charter party could specify a different threshold (Beaufort 3 / Douglas 2, which would substantially narrow the good-weather sample and favor the owner) and that threshold would govern. Parties reviewing charter party descriptions should check the specific weather conditions stated, not assume the industry default applies.

Performance claim calculations involve a cascade of estimated inputs: observed speed from distance-run log data, fuel consumption from tank sounding, draught from loading records, current from hindcast models. Each estimate carries uncertainty. LMAA arbitrators are experienced in quantifying and carrying forward these uncertainties; the outcome of a contested claim is seldom a binary win or loss but rather a discounted award reflecting the tribunal’s assessment of evidentiary quality.

The interaction between off-hire and simultaneous charterer-caused delays (port congestion, cargo hold delays ordered by the charterer) is particularly complex. If the vessel is off-hire for a mechanical breakdown but simultaneously waiting at anchorage under charterer’s orders, the off-hire may reduce or eliminate the charterer’s loss, affecting the claim quantum even if the breach is established.

Related wiki articles

• Time Charter Party
• NYPE 2015 Time Charter Form
• Charter Party Speed and Consumption Warranties
• Voyage Charter Party
• Bareboat Charter Party
• Laytime
• Demurrage
• Loss of Hire Insurance
• Force Majeure in Shipping
• Marine Engine Performance Monitoring
• BIMCO CII and Emissions Clauses
• Slow Steaming and CII
• Marine Voyage Planning and Routing

See also

• Off-Hire Deduction (NYPE)
• Charter Off-Hire Credit (NYPE / Baltime)
• Charter Off-Hire Grace Period Deductible
• Charter Time Charter Equivalent (TCE) Voyage
• Charter Withdraw Vessel for Unpaid Hire
• Hull Performance Speed Loss ISO 19030