What you need to perform it
Primary qualification
- A proven plumbing trade — in Spain, typical routes: the professional certificate in Plumbing and Domestic Heating/Air Conditioning (IMAI0108) or vocational training in thermal and fluid installations (as a guide); lines hire on demonstrable experience, not diplomas.
- Manufacturer-specific training in marine sanitary vacuum systems (Evac, Jets) — usually delivered by the company or the shipyard (as a guide).
- Valid seafarer medical certificate per flag.
Basic STCW
- STCW Basic Safety Training (A-VI/1) to sign on.
- Crowd Management (A-V/2) per muster list (Regulation V/2, passenger ships).
- Security awareness training (A-VI/6-1).
Specific courses
- Onboard potable-water sanitation: the water chapters of the USPH/VSP manual and the WHO Guide to Ship Sanitation as operating references.
- Legionella prevention and control — in Spain, RD 487/2022 applied by analogy to the ship’s installations (as a guide).
- Confined spaces and work permits (water tanks, mains) and hot work for pipe welding.
- Working knowledge of MARPOL Annex IV (sewage): what may be discharged, where, and the role of the treatment plant fed by the mains.
Indicative experience
As a guide: 3-5 years of industrial or large-building plumbing and a first onboard contract as an assistant before running the shift alone. On large ships the team is 2-6 plumbers on rotating call; the usual volume is dozens of daily jobs, with vacuum blockages from improper objects as the star breakdown.
Observations
Typical route: shore plumber → Ship Plumber → lead plumber → hotel services technician within the engine department; a sibling trade to the Refrigeration Technician (see profile) inside the hotel-technical team reporting to the Chief Engineer (see profile). Professional judgement: with potable water there are no shortcuts — a cross-connection or a poorly logged chlorination shows up in the USPH inspection and can cost the ship’s score; the daily records are worth as much as the wrench. The position barely exists on small merchant ships: it is a profile created by the hotel scale of cruise ships.
What this role does
With more than 3,000 cabins, a plumbing failure is not an inconvenience: it can disable whole decks and end in passenger compensation. The heart of the trade afloat is sanitary vacuum — ship-specific technology with two dominant manufacturers (Evac and Jets) — and potable-water sanitation, where the plumber is the first line of the USPH/VSP and legionella-prevention programmes. It is a converted shore trade: what changes are the marine materials, the spaces and the pressure of a floating city that cannot run out of toilets.
Typical watches
- Maintenance day work with 24/7 on-call rotations for sanitary breakdowns
Key responsibilities
- Maintain the vacuum toilet system (thousands of units): blockage clearing, discharge valves, vacuum ejectors/pumps and sectional vacuum-loss diagnosis.
- Keep up the potable water, domestic hot water, grey water and drainage networks of cabins, galleys, laundries and public areas.
- Run the potable-water sanitation programme: residual halogen, anti-legionella temperatures, tank cleaning and records for USPH/VSP and SHIPSAN inspections.
- Protect the network against backflow and cross-connections (backflow preventers) and keep strict separation between potable water and technical systems.
- Respond to breakdowns with hotel impact (cabins without bathrooms, galleys without water), prioritising by occupancy and coordinating with reception and housekeeping.
Operational scope
- The ship’s complete sanitary network: cabins, galleys, laundries, public and crew areas
- Sanitary vacuum plants and mains to the sewage treatment plant
- Tanks and water-production plants alongside the engine department
Profile reviewed by HydroAbyss (2026). Cited rules and timeframes are indicative: the final requirement is set by the flag State, the Administration and each company.