Skip to main content
Home/ Industries/ Maritime and marine
Cruisers · Marine · Shipbuilding

Enclosed space.
H₂S and NH₃
Crew safety.

Ships and cruise vessels are closed systems. Hydrogen sulphide (H₂S) from the drains can be deadly in the cabin or engine room. P-traps dry out due to tilt, vibration, and forgotten cabins. Green Drain™ is a mechanical one-way barrier that backpressure from the sewer does not open.

NSF/ANSI 2EN 1253−40 °C / +100 °CSalt resistant
>99.9 %
H₂S and odours
Quiet
No vibration
5 years
Life
0
Maintenance
Problem & solution

A ship's drainage has problems of its own.

The vessel pitches, rolls, and vibrates. The P-trap isn't static. A P-trap in the cabin can empty due to water movement. Plus the enclosed space — H₂S that on land would escape through a window here accumulates in the cabins.

Without Green Drain™

  • The P-trap dries out from water displacement caused by waves and machinery vibrations.
  • H₂S from blackwater — lethal above 100 ppm, human odour detection threshold 0.5 ppm
  • Cruise ship cabins — seasonal, empty for weeks — P-traps dried out
  • Engine room — central discharges under CO₂ and H₂S loading
  • MARPOL Annex IV governs the prevention of pollution by sewage from ships.

With Green Drain™

  • Mechanical one-way seal — sewer pressure does not open it.
  • Vibration and heel empty nothing — there is no water left to lose.
  • Resistant to saline atmospheres and marine cleaning agents
  • Quiet in operation — a guest in a cruise cabin won't hear the P-trap from the neighbouring cabin.
  • Safety: H₂S and methane remain in the sewer system.
Adriatic shipping

The Adriatic — a maritime heartland.

Croatian shipyards (Uljanik, 3. maj, Brodosplit, Trogir), maritime companies (Jadrolinija), the ACI marina network, and cruise terminals in Split, Dubrovnik, and Kotor represent significant market potential. MARPOL Annex IV governs the handling of sewage from ships, which is directly linked to the drainage system.

ACI
Network of marinas along the Adriatic (check the exact number at aci-marinas.com)
MARPOL IV
Annex IV — Management of Blackwater on Ships
one hundred parts per million
H₂S lethal level (reference: OSHA/NIOSH)
Classification
Bureau Veritas, Lloyd's Register, RINA — technical compliance
EN 1253
Compliance with the European standard for P-traps
0
Chemicals in P-traps — fewer hazardous substances on board
Data Sources and Regulatory Framework (2024–2025 data)

Statistical data were taken from official sources: State Statistical Office (data.dzs.hr) Croatian Institute of Public Health (hzjz.hr), Ministry of Labor, Pension System, Family and Social Policy (mrosp.gov.hr), Agency for Science and Higher Education (azvo.hr), Ministry of Tourism and Sports (mint.gov.hr). Regulatory framework: EUR-Lex for EU directives and regulations — Regulation (EU) 2017/745 (MDR), Regulation (EC) No 178/2002 (general principles of food law), Regulation (EC) No 852/2004 (food hygiene — HACCP obligation), Regulation (EC) No 1935/2004 and Regulation (EU) No 10/2011 (food contact materials), Regulation (EU) No 528/2012 (BPR), Directive 2014/34/EU (ATEX). Standards: EN 1253-1 (floor P-traps, water seal ≥50 mm), EN 1253 Parts 6/7/8 (gullies with a water seal below 50 mm, with mechanical closure, and combined types; 2023 editions), ASSE 1072-2020 (floor drain trap seal protection devices) and NSF/ANSI 2 (food equipment). HACCP International RG-04 is a private certification programme operated by HACCP International, not an official certification issued by a public authority. Tourism data taken from the DZS publication for H1 2025, healthcare data from the HZJZ report 2024, data for education from DZS publications for the 2023/2024 and 2024/2025 school years, data for nursing homes from the MROSP report, and announcements of EU-funded construction in 2025. Revision date: May 2026.

Implementation

Fitted in the shipyard or dry dock.

The ideal time is during a regular ship dry dock. Cabins, washrooms and engine rooms are all fitted during the planned dry dock.

01

Technical analysis

Review of vessel documentation and drainage systems — compliance with the classification society.

02

Pilot cabins

10 cabins and one engine room — pilot during the voyage.

03

Dry dock

The entire vessel is undergoing a planned overhaul.

04

Certification

The classification society records it in the ship's documents.

Model Recommendation

Recommended sizes by shipboard zone.

The Croatian maritime industry includes cruise ships, Jadrolinija (RoRo ferries, high-speed vessels), ACI marinas, and shipyards (Uljanik, Brodosplit, 3. maj, Trogir). Ship cabins are 50–58 mm standard, crew sanitary facilities and technical spaces are larger. Specific challenges: vibrations, salty atmosphere, MARPOL Annex IV.

Green Drain™ Recommended for your industry.

  • Cabin interiors of cruise ships, passenger ships, and RoRo ferriesGD 2. ISO/SOLAS construction standard.
  • Shipboard restaurants and cafésGD 3HoReCa standard on passenger ferries.
  • Ship's galley and engine roomGD 4Vibration defeats a water trap — this seal does not depend on water.
  • Cargo deck (RoRo, container)GD 5 or GD 6.
💬 Not sure of the exact size? Send us a photo of your sink drain — our technical team will respond with a written recommendation within the same business day, free of charge.
Check out Green Drain™ → Request a quote
GD 2
50–58 mm · cabins
GD 2.5
55–65 mm · crew sanitary facilities
GD 3
75–85 mm · ship's restaurants
GD 3.5
89–100 mm · large shower zones
GD 4
102–110 mm · galley, engine room
GD 5/6
120–135 mm-150 · cargo deck
Questions

What we get asked most.

Will the classification society accept it?

Technical documentation and compliance with EN 1253 and NSF/ANSI 2 are submitted to the classification society during the audit. The specification is in line with the general approach for sanitary systems.

Is it resistant to machine room vibrations?

The seal operates mechanically — it's not like a P-trap that relies on water. Vibrations don't affect it. Tested in industrial environments with constant vibrations.

And the salty atmosphere?

The silicone material is resistant to a saline atmosphere and UV. The external plastic frame is as well. Typical expected service life: about 5 years under marine conditions.

Complete solution

Three products.
One protection portfolio.

Green Drain™ doesn't work alone — for maximum drain control it's combined with GD Uri-Tabs™ (urinals) and GreenSwirl™ (drain unblocking).

Ready for Free audit?

We come to the site, map the drains, and provide a written recommendation — no cost, no obligation.