Koninklijke Vereniging - Société Royale



Vessel STS (Ship to Ship) clearance – A need for standardisation

Each tanker owner has to assess the suitability or compatibility of nominated vessels for loading or discharge via ship-to-ship transfer, which is an industry practice.

In this article, DYNAMARINe comments on the proposed documents required for such assessments by tanker owners who should ensure safety and compatibility of the operation, according to latest OCIMF STS guidelines.[1]
The assessment of suitability or compatibility are procedures, initiated by charterers, who expect to receive the consent of the owner and the Master with respect to the nominated vessel and not with respect to the operation itself, since it is a contractual commitment as part of the charterparty STS or other relevant rider clauses.

An assessment of a vessel(s) compliance for an STS operation takes in the vessel’s suitability (safety related) and the assessment on vessel compatibility (equipment related). These two assessment concepts are different and may take place either simultaneously or instead the suitability part may precede the compatibility assessment.

In some cases, the timecharterer may request that the owner revert on the consent on nominated vessel suitability. This action takes place for two reasons.

The first goal for the charterer is to exercise due diligence with respect to participating vessel(s) compliance, while the second goal is to provisionally receive Master’s/owner’s confirmation (with or without subjects) on nominated vessel(s) suitability assessment, as far as safety is concerned always on the basis of acknowledged industry standards.

If any subjects are raised by the owners, these should be associated with safety issues and not related to the scope of transferring cargo via STS operations.

Compatibility assessment is related to the proper rigging of mooring, primary and secondary fendering. With some vessels, special arrangements of the hull geometry are also examined.

Such assessment usually takes place by the service provider involved, as part of its duties within the Joint Plan of Operations. Since each Master is aware of his/her own vessel characteristics, it is prudent for the Master and owner to provide confirmation on vessel compatibility.

According to the latest OCIMF STS guidelines the Master has the overall responsibility of the STS operation, as outlined at sections 1.5.1 and 3.1, which state:
1.5.1) The Master of each vessel shall always remain in command of his vessel, crew and cargo, and shall under no circumstances permit safety to be jeopardised by the actions of others.

3.1) For all ship to ship (STS) transfer operations, each Master remains at all times responsible for the safety of his/her own ship (crew, cargo and equipment) and should not permit safety to be compromised by the actions of others. Each Master should ensure that the procedures recommended by this guide are followed and, in addition, that internationally accepted safety standards are maintained.

In some time or spot charters, the STS clause mentions that the operation is subject to prior approval from the Master and owner as shown below:
“...If charterers require a ship-to-ship transfer operation or lightening by lightering barges to be performed then all tankers and/or lightering barges to be used in the transhipment/lightening shall be subject to prior approval of owners, which is not to be unreasonably withheld, and all relevant certificates must be valid....”

Owners approval does not constitute an approval to the STS operation. This is thoroughly explained and justified at the FALCONERA VS ARCADIA ENERGY court award[2] where the Judge Mr Justice Eder points out the following:
“Thus, under the charter, the owners are not entitled to approve (or to refuse) the proposed STS transfer: their right of approval is limited to a right to review the details of the nominated vessel and to decide whether or not she is suitable for STS operations. In my judgment, this makes commercial sense. Once the nominated vessel is approved as suitable, all STS transfers require proper detailed planning.”

Since the Master is responsible for the safety of the operation, according to latest OCIMF guidelines, his/her final assessment on suitability is a prerequisite prior to conducting the operation. If the Master considers that the nominated vessel(s) is not considered as suitable, then such concerns should not be unreasonable and should always be related to safety issues.

Some cargo owners/charterers undertake the vessel suitability assessment, when considering vessels on subjects for STS, prior to nominating such vessels to timecharter owners, according to their internal policies and procedures. In this case, suitability of vessel(s) has been satisfied for the cargo owners/ charterers, while Masters are entitled to assess the compatibility.


Vessel suitability or compatibility assessment is based on an examination of a vessel’s characteristics and status, such as seaworthiness, statutory compliance, classification, mooring apparatus, vessel dimensions and displacement, cargo quantity and type.

Such an assessment takes place by presenting documents containing such information. Each technical operator interprets the required documents on the basis of his/her understanding and sometimes this exercise creates confusion for charterers by an unreasonable burden on document management.

There is a need to unify the assessment process, either for vessel suitability or compatibility, in order to standardise the process and support it by the exchange of important documents.

It is of upmost importance to ensure that any documents presented for each vessel are truthful and correct with respect to the information conveyed. When a Master or owner exercises his/her due diligence by examining documents for a nominated vessel, it has to be accepted that the counter owner whose vessel is being examined, provides the correct information.

STS compatibility checks

For the assessment on STS compatibility the following documents are considered as a minimum:

  1. Q88.
  2. Vessel Mooring arrangement and or GA, which shows the exact location of mooring gear.

Based on the above information, the Master confirms the compatibility of vessels and may confirm same to the charterer or raise any technical compatibility issues that need to be addressed prior to carrying out an STS operation.

Should a service provider be appointed, he/she may be consulted and assist the Master in this respect.
Subsequent to the above confirmation on compatibility due diligence check required by charterers, the Master may seek additional assurance that the appointed STS service provider and Mooring Master can provide the expected quality of assistance, as per OCIMF guidelines and IMO regulations. Charterers do not provide any assurance, or any other information regarding the quality assurance that is being carried out on service providers, thus, in certain cases tanker operators may request the following:

  1. A brief questionnaire from the service provider that he has the necessary procedures in place;
  2. Brief questionnaire from the Mooring Master that ensures that he/she has the necessary experience and qualifications described in the IMO’s Manual on Oil Pollution and latest OCIMF guidelines;
  3. Maintenance certificates of equipment to ensure that the proper maintenance of STS equipment is carried out;
  4. A joint plan of the operation, which cover all topics required in the OCIMF guidelines.

STS suitability assessment

For the STS assessment on suitability our opinion is that the following documents should be required as a minimum:
Q88. This is the standard questionnaire for tanker vessels. It conveys all the necessary information for vessel characteristics/ documentation and mooring gear.

IOPP FORM B. This is required to prove that an STS Plan exists on board.

STS PLAN. This is required as evidence that the STS Plan has been developed with the technical operator present, as it may be part of the SMS and furthermore, if the plan has been developed as per the latest OCIMF guidelines. This is a Marshall Islands requirement for registered vessels, as well as a OCIMF VIQ requirement, as per question 8.84 of latest VIQ.

P&I entry certificate, which ensures that the vessel is entered with an IG P&I club. This is to ensure that the $1 bill availability guarantee for oil pollution and will show if there is a club exclusion or special deductible on RDC for STS purposes. Some P&I clubs have issued special conditions for vessels participating in STS operations.

A recent class status, to show if the vessel has any outstanding recommendations, which might affect the STS performance, such as a displaced chock, missing anchor, non-operating D/G, STS plan non-conformity, damage on side shell plating from a previous STS.

Other documents such as CLC, DOC, SMC, Certificate of Registry are not considered as mandatory for the assessment on suitability, unless a discrepancy is shown during the clearance.

For example, it has been noticed in some Q88 questionnaires that the available number of closed chocks does not correspond to the actual equipment and hence a mooring arrangement may be requested. Also in a case where the DOC holder shown on Q88 is not consistent with class status or web data, then the DOC and SMC certificates may be requested as a further source of evidence.

Furthermore, for some vessels which participate in STS operation for the first time or other reasons associated with safety, the STS experience matrix could be requested.
In some regions, such as the US, specific questionnaires are requested for lightering purposes, such as the ITOL questionnaire. This questionnaire covers most of the data included in the Q88 apart from the following:

  1. Brake capacity and MBL of mooring gear and lines. This data is used to check if rendering of brake load on mooring gear is necessary on the larger tanker.
  2. Crew working language is not available at the ITOL, apart from item 192 where it mentions English understanding for Master and C/O. We consider that multiple crew nationalities.

Late last year, DYNAMARINe unveiled an STS e-learning course, which applies to either shore or ships personnel.
It covers information related to due diligence and best practices issues to assist participants mitigate risks, while protecting shipowners interests.

Topics covered include general STS operations, planning an operation, safety procedures, vetting issues, self-assessment versus rules/regs and incident investigation.

The course applies to deck officers, ratings, ship operators and safety and quality operators and is provided online via a specialised training platform.

Upon completion and final examination, participants will receive a certificate of completion from DYNAMARINe Academy, certified by ABS.




  1. OCIMF/SIGTTO/ICS/CDI, Ship to Ship Transfer Guide for Petroleum, Chemicals and Liquefied Gas, 2013.
  2. Bristol Crown Court BS1 1DA, 20/12/2012, Neutral Citation Number: [2012] EWHC 3678.



  LMB-BML 2007 Webmaster & designer: Cmdt. André Jehaes - email
 Deze site werd geoptimaliseerd voor een resolutie van 1024 x 768 en IE -11-Edge
Ce site a été optimalisé pour une résolution d'écran de 1024 x 768 et IE -11- Edge