Oil tanker · Liberia flag · built 2008
MARIANN: CO₂ emissions 2019–2025
IMO 9326897 EU ETS6 reporting years
- CO₂ reported 2025
- 6,472 t
- Fuel burned
- 2,050 t
- Distance
- 14,655 nm
- Time at sea
- 2,117 h
- Emitted at berth
- 6% of total
- Share of year under way
- 24%
- Gross tonnage
- 42,996
MARIANN against its type
Built in 2008, it is 2 years older than the median oil tanker on this register, which was built in 2010 (2,896 vessels with a known build year). At 42,996 gross tonnage it is smaller than 60% of the other 2,841 oil tankers with a recorded tonnage. It is one of 718 oil tankers here under the Liberia flag, 20.2% of the 3,548 on the register. The same builder is recorded for 56 other vessels here, 24 of them oil tankers. Its MRV returns name it MARIANN for 2019–2020, ORTOLAN COCO for 2021–2022 and ROMEOS for 2023–2025. The reported port of registry changed: Longyearbyen (2019–2020), then Monrovia (2021–2025).
Its 6,472 t of CO₂ for 2025 is 18% below the median of 7,922 t among the 1,704 oil tankers on this register that reported for 2025. Per nautical mile it emitted 441.6 kg CO₂, close to the type median of 403.2 kg. It logged 2,117 hours at sea against a median of 2,030 hours for its type that year. 6.0% of its 2025 emissions were at berth; the median for oil tankers was 7.8%. Across 6 years with reported emissions, the highest was 2022 (11,372 t) and the lowest 2023 (628 t). Its efficiency percentile within the type went from 54 in 2019 to 73 in 2025 (lower is more efficient). The one sister ship listed below with a 2025 return reported a lower CO₂ per nautical mile.
Emissions by year2019–2025
| Year | CO₂ (t) | Fuel (t) | Distance (nm) | At sea (h) | At berth (t) | kg CO₂/nm | EEOI | Percentile |
|---|---|---|---|---|---|---|---|---|
| 2025 | 6,472 | 2,050 | 14,655 | 2,117 | 390 | 441.6 | 10.2 | 73 |
| 2023 | 628 | 196 | — | 124 | 0 | 431.9 | — | — |
| 2022 | 11,372 | 3,580 | 28,996 | 2,641 | 1,559 | 392.2 | 8.6 | 56 |
| 2021 | 5,639 | 1,800 | 17,087 | 1,646 | 163 | 330.0 | 8.0 | 46 |
| 2020 | 5,156 | 1,651 | 12,815 | 1,032 | 76 | 402.3 | 11.8 | 70 |
| 2019 | 3,564 | 1,142 | 10,648 | 1,323 | 35 | 334.7 | 8.9 | 54 |
Vessel particulars
- IMO number
- 9326897
- Previously reported as
- ORTOLAN COCO, ROMEOS
- Ship type
- Oil tanker
- Gross tonnage
- 42,996
- Length overall
- 228.6 m
- Beam
- 32.3 m
- Year built
- 2008
- Flag state
- Liberia per EU MRV 2025
- Builder
- Brodosplit
- Port of registry
- MONROVIA MRV 2025
- Ice class
- IA
- Technical efficiency (design)
- EEXI (4.07 gCO₂/t·nm)
- Verifier
- Bureau Veritas Certification France, France
- Accreditation
- 3-2047 rev. 4
- Compliance document issued
- 2026-03-24
- Compliance document expires
- 2027-06-30
Efficiency against its own type2025
Position 1,052 of 1,448 qualifying oil tankers by EEOI, at the 73rd percentile. The dashed line is the type median, 7.5; this vessel reported 10.2.
EEOI divides emissions by transport work, which for this vessel and year was 636,958,661 tonne-miles over 14,655 nautical miles.
Reported CO₂ by year
Reported CO₂ in 2025 was 81.6% higher than in 2019, for EU/EEA voyages only. No return is recorded for 2024, so the series has gaps.
From 2023 to 2025, emissions rose 930.4% and CO₂ per nautical mile rose 2.2%.Distance is missing for at least one of the two years, so activity and efficiency cannot be separated here.
Where the 2025 emissions occurred
Methane, nitrous oxide and EU ETS2025
- Total CO₂ equivalent
- 6,572 t
- Methane (CH₄)
- 0.10 t
- Nitrous oxide (N₂O)
- 0.37 t
- Under EU ETS
- 3,431 t, 53% of total
Verifier history
| From reporting year | Verifier | Accredited in |
|---|---|---|
| 2019 | DNV | Germany |
| 2023 | Bureau Veritas Certification France | France |
A change of verifier is not in itself a sign of anything being wrong.
Sources and how to read this
- Emissions: EU MRV publication (THETIS-MRV), reporting years 2019–2025, published by the European Commission.
- Vessel particulars: Wikidata (CC0).
This page draws on 6 MRV reporting years, an efficiency ranking, 5 of 5 vessel particulars and a name history. Not found in the sources for this vessel: AIS movements in Norwegian waters, a licensed photograph, a sanctions listing and US port state inspections.
Empty means unreported, never zero. How EEOI, distance, percentiles and sister ships are handled is explained under reading a vessel page. Something wrong? See corrections.