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Observater Surveys and Services Group · Cotonou · Benin
Our bunker surveyors in Cotonou attend every fuel event a vessel has: bunker quantity surveys at the stem, on-hire and off-hire ROB surveys, intermediate and redelivery soundings, bunker shortage investigations, and MARPOL sampling, with who attends, when, and on what basis confirmed in writing before work begins.
Shipowners, charterers, bunker buyers and traders, P&I clubs, and suppliers in dispute all instruct the same group, under one rule: one interest per matter.
Get a Surveyor Moving Email the InstructionThe fuel level is froth, not fuel. Air pumped into the delivery line makes the sounding read high. Days later the level settles, and the shortage that was always there appears, unclaimable.
The temperature on the note is not the temperature in the tank. Fuel expands with heat, and a few recorded degrees change the tonnes. Independent thermometers and density checks keep the correction honest.
The charter ends and the fuel argument begins. On-hire and off-hire ROB figures set who pays for what remains on board. Without independent soundings at both ends, the settlement is a negotiation, not a calculation.
Cotonou tests the fuel account its own way. Vessels stem fuel at Cotonou at the berth and at anchorage, and every stem is one of the largest single payments the ship makes in port. One independent surveyor on deck is the difference between paying for what was received and paying for what the paperwork says.
One call at a port often opens several files — the cargo, the fuel, the vessel itself — and our team holds them all. Step into the unit your matter needs; one instruction line carries the rest.
Our highly trained bunker surveyors carry out all types of bunker surveys, bunker quantity surveys, and marine fuel inspections at Cotonou Port, Benin, through our own local surveyors at the port, with every attendance confirmed in writing before work begins: stems, on-hire and off-hire ROB, intermediate soundings, redelivery, shortage investigations, and MARPOL sampling, on all fuel grades. Vessels stem fuel at Cotonou at the berth and at anchorage, and every stem is one of the largest single payments the ship makes in port. Also see: cargo surveyors in Cotonou and marine surveyors in Cotonou.
A bunker quantity survey at Cotonou puts an independent surveyor on your side of the manifold for the whole stem. We sound the tanks on both the receiving vessel and the barge before pumping starts and after it ends, refusing to rely on the supplier’s figures or the ship’s automated gauges alone. Temperatures are taken with our own calibrated instruments, densities are checked against the delivery note, and observed volumes are corrected to standard volume at 15°C under the ASTM tables, so the tonnes on paper are the tonnes in the tank. Where the figures do not hold, the letter of protest is drafted and issued as part of the attendance, while the barge is still alongside and the evidence still exists.
On-hire and off-hire bunker surveys at Cotonou fix the fuel account at the two moments a charter pays for it. We sound fuel oil, diesel, and lube oils independently, apply trim and list corrections from the vessel’s own hydrostatic data, account for unpumpables and sludge, and certify the remaining-on-board quantity both sides can settle against. The same attendance records the vessel’s condition, so the delivery-against-redelivery argument is answered by one document instead of two memories.
Where a stem is disputed at Cotonou, the desk moves from figure to cause: line displacement checked, temperature and density verified against the delivery note, and the difference stated in writing with the working attached.
When the delivered figure and the paid-for figure refuse to meet, or fuel keeps disappearing faster than the engines burn it, the question stops being measurement and becomes investigation. Our bunker shortage investigations in Cotonou follow the fuel until the numbers explain themselves.
The delivery note says one figure, the settled tanks say another. We re-sound after an enforced settling time, test density from the sample, recalculate on measured temperatures, and put the difference in a letter of protest the claim can stand on.
When burn rates outrun the engines’ appetite voyage after voyage, we audit the fuel account: soundings against log entries, bunker delivery notes against measured densities, and every transfer between tanks reconciled.
Where concealment is suspected, standard sounding is not enough. Our investigators trace the transfer piping physically, check void spaces and non-nominated tanks, verify sounding pipes against alteration, and test calibration tables against the actual steel.
Every finding is photographed, timed, and placed, and the report is written in the form P&I clubs, underwriters, and tribunals accept, so what the investigation finds, the claim can use.
Fuel quality disputes are won on the sample, and the sample is only as good as its chain of custody. Our surveyors witness the continuous drip sample at the manifold, the official point of custody transfer, then seal, label, and document it on the bunker delivery note, so the vessel holds the legal armor a Port State Control inspection or a quality dispute demands. Where off-specification fuel must come off, de-bunkering is supervised and measured with the same discipline as a delivery, so every tonne leaving the ship is accounted for.
Shipowners & managers. The fuel account defended at every stem and both ends of every charter in Cotonou, with ROB figures that settle instead of argue.
Charterers & operators. Independent verification that the fuel paid for went into the tanks, and that redelivery quantities are calculated, not conceded.
Bunker buyers & traders. A surveyor on the manifold during the stem is the cheapest insurance a fuel purchase can carry: measured delivery, honest corrections, protest on the spot.
P&I clubs & correspondents. Impartial attendance, one appointment per matter, and shortage findings documented in claim-ready form the same day.
Suppliers with a dispute. When a delivery is challenged, independent measurement protects the honest party, whichever side of the manifold they stand on.
Lawyers & claims teams. Soundings, samples, photographs, and calculations tied to time and place: a fuel file built for the argument that follows.
Named surveyor, scope in writing. Before anything starts you know who attends, when, and exactly what they will do, on paper.
The fee agreed first. The fee is put in writing before work begins, so the decision is made with the numbers in front of you.
One interest per matter. If we act for the other side in your dispute, we tell you and decline. Independence is the product.
Work starts on your go-ahead. Nothing begins until you confirm in writing, and the findings reach you first, in confidence. We answer 24/7.
“The surveyor held the stem for settling when the tanks read high, and the re-sounding proved the shortfall. That one attendance paid for the year.”Charterer, Cotonou
“Off-hire ROB was heading for a deduction until the joint survey corrected the trim calculation. Both sides signed the same figure.”Vessel operator, Cotonou
“Density tested from the sample did not match the note. The protest was issued before the barge let go, and the invoice was corrected.”Bunker buyer, Cotonou
Attendance in Cotonou is arranged on instruction through our own local surveyors at the port, with every attendance confirmed in writing before work begins: send the vessel, the terminal or anchorage, and the stem size, and who attends, when, and on what basis is confirmed in writing before work begins.
The fee depends on the scope: the service, the stem size, and the attendances needed. Scope and fee come back in writing before work begins, and one prevented short delivery typically covers many surveys.
A bunker survey in Cotonou measures the fuel independently at an agreed event: tank soundings on the vessel and the barge, temperatures and densities on calibrated instruments, correction to standard volume at 15°C, verification against the bunker delivery note, and a report with the calculations and evidence attached, with a letter of protest issued where the figures do not hold.
Yes. Where the delivery is already signed, our shortage investigation reconstructs the fuel account from soundings, logs, delivery notes, and samples, and where concealment is suspected an investigative 221B survey physically traces the piping and checks non-nominated spaces. The earlier we attend, the more evidence survives.
From the gap between what was declared and what was measured. Air entrained in the delivery, generous temperature assumptions, and a shore figure taken on trust all move money quietly. An independent surveyor sounding the tanks on both sides of the operation turns each assumption back into a measurement.
Observater Surveys and Services Group are the bunker surveyors at Cotonou Port, Benin — our own local surveyors at the port, attending at berth and anchorage on one instruction line, with the surveyor’s name, scope, and fee confirmed in writing before work begins.
Every matter is quoted on its scope before attendance — in writing, with the surveyor named. That way the instructing party knows the cost before the gangway, not after the invoice.
A routine quantity survey runs with the operation it witnesses: soundings before, attendance through the stem or transfer, soundings after, and the figures reconciled the same day. Delivery volume and access set the hours; the report follows promptly with the working attached.
The figure taken today settles the argument that comes later
Send the vessel, the terminal or anchorage, the ETA, and the stem size, and we confirm who attends, when, and on what basis, in writing, before anything starts.
Get a Surveyor Moving Email the InstructionThe same group, the same report standard, along the same trade routes: Bunker surveyors in Lomé · Bunker surveyors in Tema · Bunker surveyors in Lagos · Bunker surveyors in Douala.
International Marine Cargo Surveyors, Claims Handlers and Technical Consultants in Africa. On-ground expertise, global reach: anywhere you go in Africa, we are already there, with capacity to serve globally.
Observater Surveys and Services Group · ops@observater.com · All attendances are performed under our standard terms of business, available on request. Also see: Cargo Surveyors in Cotonou · Marine Surveyors in Cotonou · Benin · Africa Bunker Survey Experts · Bunker Surveys in Djibouti.
From the Observater Desk
Whatever the vessel question, the cargo below has its own: outturn against the manifest, tally at the hook, condition as found, and the claims file that follows. The cargo desk at Cotonou answers it from the same practice, one instruction covering both.
Cargo surveyors in CotonouInstruct the desk
When precision matters, Observater Surveys Group is your Partner of Choice
© 2026 Observater Surveys and Services Group. All rights reserved.