On / Off-Hire Bunker & Condition Survey: A Practical Guide

Delivery and redelivery are the two moments in a charter where the commercial and the technical sides of a vessel meet in one set of figures: fuel remaining on board, and the state of hull, deck and accessible spaces — the reference point both parties argue from later.

An on/off-hire bunker and condition survey makes it a single, shared one: one independent surveyor attends, measures, observes, and issues the same report to both sides. This guide sets out what the service covers, how the attendance runs, and what preparation on board makes the record stronger.

What the Survey Covers

The bunker element establishes the vessel’s ROB — Remaining On Board — by sounding and calculation at delivery and again at redelivery, so the quantity change across the charter period rests on two figures taken on a consistent basis. Within the agreed scope, ROB is recorded tank by tank and grade by grade, not as a single total. Consistency is the point: the same sounding or ullage method at both ends, the same correction basis, density established on the same basis at each end, and quantities stated on the same basis — weight in air or weight in vacuum, which are not interchangeable. Which basis applies, and on what documents, belongs in the survey instructions before the first attendance, not discovered at the second. For the same reason the two ends are compared in mass, not in observed volume: the same fuel occupies a different volume once its temperature changes.

The condition element is a general visual review of the hull, deck, and accessible spaces at the time of attendance, recorded alongside the bunker figures. It is not a class survey, and it is limited to what is visible on the day: deck, the visible portions of the hull, and the spaces opened for it. The underwater hull, tank internals and anything behind closed structure fall outside it unless separately agreed. It describes the state in which the vessel was handed over or handed back, recorded by someone with no commercial stake in the outcome.

How the Attendance Is Carried Out

The detail varies with vessel type and terms agreed, but the order holds.

Scope confirmation before boarding. What is being surveyed and why: delivery or redelivery, tanks in scope, spaces to be accessible, who else attends, and documents expected on board.

Arrival, vessel condition, and context. On boarding, the surveyor records the circumstances the measurements are taken in — draughts, trim and list, the operational state, and anything constraining the work. Trim and list are not background detail: they decide how a sounding converts into a volume.

Tank-by-tank measurement. Bunker tanks within the agreed scope are sounded or ullaged, temperatures taken, and — where the arrangement permits — a water dip carried out with water-finding paste at the lowest accessible sounding point. Where remote gauges are fitted, the reading is cross-checked against a manual sounding rather than relied on alone, wherever the tank arrangement and the safety regime allow it; on a closed-gauging installation that cross-check may not be available, and the report then states what the figure rests on. Readings are converted to volume on the vessel’s own calibration tables with the trim and list corrections those tables provide; that volume is corrected from the observed temperature to the standard reference temperature and converted to mass using the density of the fuel actually in the tank, not a nominal grade value. In heated tanks, temperature is taken at more than one depth: fuel on steam coils is rarely the same temperature top to bottom, and a single reading near the coils skews the correction. Free water found is recorded and deducted rather than carried inside the fuel figure; sludge or sediment is recorded for what it is, not absorbed into the fuel quantity. Keeping them visible and separate is a measurement discipline, not a commercial one: what the charter party then makes of an unpumpable or water-bearing residue is a separate question, and the point of the record is that the figures are there to answer it. Whether the fuel meets its specification is a separate analysis. Transfers between tanks and any bunkering are stopped for the measurement where operations allow: the surveyor asks, the master decides, and the time of measurement is recorded either way. Where a tank cannot be measured properly — an obstructed sounding pipe, an unreliable gauge — that is recorded as a limitation, not quietly estimated.

Condition walk-through. The purpose is description, not grading: what is there, where, and how it presented on the day. Entry into any enclosed space is made only under the permit-to-work procedures that apply — the ship’s safety management system first, with the surveyor’s own procedures and any terminal requirement — the atmosphere tested before entry and monitored during it, under the master’s authorisation. Where entry cannot be arranged on that basis, the space is recorded as not entered: a gap in the record is the correct outcome, and entering an unventilated tank to avoid one is how people are killed. Observations are supported by photographs identified by location and date — what makes a condition note a baseline rather than an assertion.

Joint acknowledgement on board. Representatives present review the figures and observations and acknowledge them where willing. What makes the document a joint record is the single independent attendance, not the signatures; a representative declining to sign does not turn it back into one party’s account — the declining is itself recorded. Disagreement is far more useful raised on the report itself, or by letter of protest before the attendance closes, than afterwards — though that is a practical step, not a contractual one: what weight the record carries, and when notice must be given, follow from the charter party, not from the survey.

Structured report to both parties. A single report of ROB figures and condition observations, issued to charterer and owner with the same content.

The Disputes This Record Heads Off

• Competing bunker figures at redelivery. When each side measures separately, two different ROB numbers appear and neither party can disprove the other. A single attendance removes the premise of that argument: one figure, taken by one method, with both sides free to be present for it. A party can still dispute the figure — but it is disputing a record it had the opportunity to watch being taken.
• Fuel grade and segregation questions. Recording which grades sit in which tanks at both ends narrows later uncertainty about what was handed over, and supplies the quantity and grade figures a redelivery bunker clause is applied to, where the charter party provides one. It does not set the price — valuing redelivery bunkers is a charter party mechanism.
• Damage attribution. Condition observations at delivery are the baseline anything found at redelivery is compared against; without one, every mark becomes a question of who caused it. The record evidences the state of the vessel at a point in time; it does not determine cause or liability.
• Scope and access disputes. A record stating plainly what could not be surveyed, and why, keeps the limits of the attendance visible — so silence in the report is not later read as confirmation that nothing was wrong.

What the Owner or Manager Should Prepare

Most of what makes an attendance efficient is already on board before the surveyor arrives. The most frequent cause of a thin report is access: a space in scope on paper but closed on the day leaves a gap. The next is paperwork — capacity tables that no longer match the ship, or no reliable density to calculate against.

• Delivery or redelivery timing and location confirmed, with as much notice as possible
• Survey scope agreed in writing by both parties — tanks, spaces, documents expected
• Current tank capacity tables on board, applicable to the vessel as it stands, not a superseded set
• Sounding arrangements accessible and unobstructed; sounding tape, gauges and water-finding paste serviceable
• Spaces in scope for the condition review safe and open at the agreed time
• Engineer familiar with the bunker arrangement, and a deck officer able to open those spaces, available
• No internal transfers or bunkering planned during the measurement window
• Recent bunker delivery notes with the density stated, and the vessel’s own ROB figures ready for reconciliation
• Any tank modification, access limitation or sounding irregularity declared before measurement begins
• A vessel representative available to review figures and observations before the attendance closes

An independent, joint record made at the delivery or redelivery itself leaves both sides with one consistent reference point, rather than two separate and potentially conflicting ones: On / Off Hire Bunker & Condition Survey.