OILER (STCW III/5) AND WIPER (STCW III/4) UNDER STCW: REGULATORY DIFFERENCES
INTRODUCTION
Within the engine department of merchant vessels, the positions of Wiper (STCW III/4) and Oiler (STCW III/5) represent different levels of professional qualification and responsibility. These distinctions are clearly established by the International Convention on Standards of Training, Certification and Watchkeeping for Seafarers (STCW), 1978, as amended, including the Manila Amendments 2010.Although these positions are sometimes perceived as similar entry-level roles, under STCW they are two distinct qualification categories, differing in:
level of competence
degree of independence
authorization to operate machinery
responsibility for safe engine room operations
requirements for training and sea service
This article explains the differences strictly within the STCW framework, without national or crewing-related simplifications.
CLASSIFICATION UNDER STCW CHAPTER III
Both positions fall under STCW Chapter III — Engine Department and belong to the Support Level, however they represent different stages of qualification.Wiper corresponds to STCW III/4, which is the basic support level.
Oiler corresponds to STCW III/5, which is the qualified support level and internationally recognized as Able Seafarer Engine.
WIPER (STCW III/4)
STATUS UNDER STCW
Wiper is a member of the engine department performing supporting and assisting duties in the engine room under direct or continuous supervision of senior engine personnel.Under STCW, Wiper is considered an entry-level engine room rating, not authorized to independently operate shipboard machinery or systems.
DUTIES OF WIPER (STCW III/4)
In accordance with STCW Code, Section A-III/4, a Wiper performs the following duties:
assisting with routine work in the engine room
cleaning, washing, and preparing machinery and equipment
assisting engineers and qualified engine ratings during maintenance and repairs
following instructions of the watchkeeping engineer
participating in emergency, firefighting, and safety operations
complying with occupational health and safety procedures
LIMITATIONS OF WIPER (STCW III/4)
Under STCW, a Wiper is not permitted to:
independently operate engine room machinery
perform maintenance tasks without direct supervision
serve as a watchkeeping engine room rating
carry out operations that directly affect vessel safety
OILER (STCW III/5)
STATUS AND QUALIFICATION UNDER STCW
Oiler is classified as a qualified engine room rating. This is not a trainee position but a trained professional who has successfully demonstrated competence in accordance with STCW Code, Section A-III/5.Under STCW, Oiler holds the qualification of Able Seafarer Engine.
DUTIES OF OILER (STCW III/5)
In accordance with STCW Code, Section A-III/5, an Oiler is authorized to:
operate and maintain shipboard machinery and engine room systems
carry out lubrication, monitoring, and routine maintenance tasks
participate in engine room watchkeeping under the general supervision of an engineer
identify equipment malfunctions and report them to the engineer
participate in repair work as a qualified engine room rating
perform duties that have a direct impact on the safety of the vessel
LEVEL OF RESPONSIBILITY OF OILER (STCW III/5)
An Oiler:
bears personal responsibility for assigned machinery and equipment
is required to understand the operating principles of engine room systems
is accountable for the safe and correct execution of assigned tasks
KEY DIFFERENCES BETWEEN OILER (STCW III/5) AND WIPER (STCW III/4)
Wiper (STCW III/4) represents a basic support level, working strictly under supervision.
Oiler (STCW III/5) represents a qualified support level, allowing independent actions within assigned duties.The differences concern:
authorization to operate machinery
participation in engine room watchkeeping
degree of independence
level of responsibility
eligibility for further career advancement
CAREER PATH UNDER STCW
STCW establishes a clear professional progression within the engine department:Wiper (STCW III/4) → Oiler (STCW III/5) → Engine Officer (STCW III/1)Progression from Wiper to Oiler requires:
documented sea service in the engine department
completion of approved training for STCW III/5
successful assessment of competence
valid STCW certification
PRACTICAL IMPORTANCE OF CORRECT CLASSIFICATION
Correct designation of Wiper (STCW III/4) and Oiler (STCW III/5) is essential for:
compliance with Flag State and Port State Control inspections
adherence to MLC 2006 requirements
correct determination of wages and contractual duties
ensuring engine room safety
lawful and transparent career development
CONCLUSION
Wiper (STCW III/4) and Oiler (STCW III/5) are distinct qualification levels clearly defined by the STCW Convention.Wiper performs assisting duties under supervision.
Oiler is a qualified engine room rating with increased responsibility and authorization to operate machinery.Understanding this distinction is critical for seafarers, shipowners, and crewing companies.
DISCLAIMER
This article is for informational purposes only and does not replace official STCW requirements, Flag State regulations, or company-specific procedures.
