Bunker Quantity Survey (BQS) in Valencia, Spain
A Bunker Quantity Survey (BQS) is an independent technical process used to determine the actual quantity of marine fuel delivered and received onboard a vessel.
VALENCIA Marine Services provides professional BQS attendance in Spanish Mediterranean ports, ensuring transparency and contractual protection during high-value bunkering operations.
Bunker Quantity Survey (BQS)
A Bunker Quantity Survey (BQS) is an independent verification process that determines the actual quantity of marine fuel delivered and received onboard a vessel through structured measurement and calculation procedures.
OBQ / ROB Survey (Charter Delivery & Redelivery)
An OBQ / ROB Survey establishes the precise quantity of fuel onboard a vessel at charter delivery or redelivery, ensuring contractual transparency between shipowners and charterers.
Detective Bunker Survey (Fuel Discrepancies & Claims Support)
A Detective Bunker Survey is a technical investigation conducted when discrepancies arise between declared and measured fuel quantities, providing structured analysis and documentation for commercial or insurance claims.
Bunker Quantity Survey (BQS)
What Is a Bunker Quantity Survey?
A BQS involves structured measurement and calculation procedures performed before, during, and after bunkering operations to verify:
Quantity delivered
Quantity received onboard
Accuracy of declared BDN figures
Temperature and density corrections
Volumetric reconciliation
The objective is to eliminate discrepancies and reduce financial exposure.
Quantity delivered
Quantity received onboard
Accuracy of declared BDN figures
Temperature and density corrections
Volumetric reconciliation
The objective is to eliminate discrepancies and reduce financial exposure.
Bunker Quantity Survey (BQS)
Scope of BQS Attendance
Our Bunker Quantity Survey may include:
Pre-Supply Measurement
Initial tank ullage/sounding measurement
Verification of calibration tables
Recording of tank conditions
During Supply Supervision
Monitoring of transfer procedures
Verification of operational sequence
Observation of manifold conditions (as accessible)
Post-Supply Measurement
Final tank measurements
Temperature readings
Density verification
Volumetric calculation with correction factors
Bunker Quantity Survey (BQS)
Calculation Methodology
Accuracy in bunker operations requires a transparent chain of calculations.
Our methodology may include:
Manual and/or electronic tank measurement
Temperature correction application
Density @ reference temperature adjustment
Volume correction factor (VCF) application
Comparison with the declared BDN quantity
Reconciliation analysis
All calculations are documented clearly in the final report.
METHODOLOGY
Calculation Methodology
Accuracy in bunker operations requires a transparent chain of calculations.
Our methodology may include:
Manual and/or electronic tank measurement
Temperature correction application
Density @ reference temperature adjustment
Volume correction factor (VCF) application
Comparison with the declared BDN quantity
Reconciliation analysis
All calculations are documented clearly in the final report.
INDEPENDENCY
Why Independent BQS Is Critical
Small quantity differences can represent a significant financial impact.
An independent BQS helps:
Prevent commercial disputes
Protect charter settlements
Support claims if discrepancies arise
Provide neutral third-party verification
Strengthen contractual compliance
VESSELS
Services by Vessel Type
This service is primarily provided for:
Merchant vessels and commercial units
Tankers
Container ships
Bulk carriers
Ferries
Large yachts & specialised units (case-by-case, high-value operations)
PORTS
Ports Covered in Spain (Mediterranean)
We attend bunker operations across Spanish Mediterranean ports, including:
Mediterranean Ports
Barcelona
Tarragona
Castellón
Valencia
Alicante
Cartagena
Other Ports
Attendance at other Spanish ports may be arranged upon request, depending on logistics and schedule.
REPORT
Bunker Quantity Survey Technical Report
The BQS report typically includes:
Recorded tank measurements
Applied correction factors
Density values used
Volumetric calculations
Observations during supply
Final delivered/received quantity determination
The report is structured to support:
Commercial reconciliation
Charter party settlement
Claims documentation
Insurance review
Bunker Quantity Survey (BQS)
When Should You Request a BQS?
You should consider independent BQS attendance when
High fuel quantities are being supplied
Previous discrepancies have occurred
Charter change is approaching
There is uncertainty regarding the declared quantity
Risk mitigation is required
FAQs
Everything you need to know now
What is a Bunker Quantity Survey (BQS)?
An independent verification of delivered/received fuel quantity based on tank measurements before and after supply and corrected volumetric calculations.
When do I need an OBQ/ROB survey?
At charter delivery/redelivery or any handover where fuel quantity impacts settlement between parties.
When is a detective bunker survey required?
When there is a material discrepancy between declared and measured quantities or when procedural anomalies require technical investigation.
Request Attendance / Get a Quote
To confirm availability and quote accurately, please send:
Vessel name + IMO (if available)
Port + ETA/ETB
Fuel grades and expected quantities (MT)
Supply method (barge/shore/truck/STS)
Required service (BQS / OBQ-ROB / Detective)
VALENCIA Marine Services
Camino del Canal 91 Real Club Náutico de Valencia Block 3 Office 21 Valencia 46024 (SPAIN)
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