Oil tanker · Marshall Islands flag · built 2009
RIDGEBURY KATHERINE Z: CO₂ emissions 2018–2025
IMO 9439797 EU ETS5 reporting years
- CO₂ reported 2025
- 2,379 t
- Fuel burned
- 755 t
- Distance
- 9,098 nm
- Time at sea
- 756 h
- Emitted at berth
- 5% of total
- Share of year under way
- 9%
- Gross tonnage
- 29,905
RIDGEBURY KATHERINE Z against its type
Built in 2009, it is 1 year older than the median oil tanker on this register, which was built in 2010 (2,896 vessels with a known build year). At 29,905 gross tonnage it is smaller than 73% of the other 2,841 oil tankers with a recorded tonnage. It is one of 793 oil tankers here under the Marshall Islands flag, 22.4% of the 3,548 on the register. The same builder is recorded for 180 other vessels here, 51 of them oil tankers. V-Ships is linked to 16 vessels on this register. Its MRV returns name it RIDGEBURY KATHERINE Z for 2018–2020 and ST. MARY for 2023–2025. The returns for 2018–2025 all give Majuro as port of registry.
Its 2,379 t of CO₂ for 2025 is 70% 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 261.5 kg CO₂, 35% below the type median of 403.2 kg. It logged 756 hours at sea against a median of 2,030 hours for its type that year. 5.2% of its 2025 emissions were at berth; the median for oil tankers was 7.8%. Across 5 years with reported emissions, the highest was 2020 (3,566 t) and the lowest 2023 (1,641 t). Its efficiency percentile within the type went from 39 in 2020 to 55 in 2025 (lower is more efficient). Of the 3 sister ships listed below with a 2025 return, 0 reported a lower CO₂ per nautical mile than this vessel.
Emissions by year2018–2025
| Year | CO₂ (t) | Fuel (t) | Distance (nm) | At sea (h) | At berth (t) | kg CO₂/nm | EEOI | Percentile |
|---|---|---|---|---|---|---|---|---|
| 2025 | 2,379 | 755 | 9,098 | 756 | 124 | 261.5 | 7.8 | 55 |
| 2024 | 3,063 | 975 | 9,315 | 1,001 | 0 | 328.8 | 9.5 | 70 |
| 2023 | 1,641 | 517 | 4,291 | 411 | 185 | 382.5 | 9.9 | 67 |
| 2020 | 3,566 | 1,139 | 13,233 | 994 | 123 | 269.4 | 7.5 | 39 |
| 2018 | 1,754 | 560 | — | 813 | 96 | 258.8 | 14.2 | not ranked |
Vessel particulars
- IMO number
- 9439797
- Previously reported as
- ST. MARY
- Ship type
- Oil tanker
- Gross tonnage
- 29,905
- Length overall
- 183.0 m
- Beam
- 32.2 m
- Year built
- 2009
- Flag state
- Marshall Islands per EU MRV 2025
- Builder
- SPP Shipbuilding Co., Ltd.
- Port of registry
- Majuro MRV 2025
- Home port
- Majuro
- Technical efficiency (design)
- EIV (6.44 gCO₂/t·nm)
- Operator
- V-Ships
- Verifier
- Nippon Kaiji Kyokai, Japan
- Accreditation
- VS-21325-01
- Compliance document issued
- 2026-03-17
- Compliance document expires
- 2027-06-30
Efficiency against its own type2025
Position 797 of 1,448 qualifying oil tankers by EEOI, at the 55th percentile. The dashed line is the type median, 7.5; this vessel reported 7.8.
Across the 14 ranked vessels operated by V-Ships, the median percentile is 59. This vessel is more efficient than its own fleet median.
EEOI divides emissions by transport work, which for this vessel and year was 303,424,745 tonne-miles over 9,098 nautical miles.
Reported CO₂ by year
Reported CO₂ in 2025 was 35.6% higher than in 2018, for EU/EEA voyages only. No return is recorded for 2019, 2021, 2022, so the series has gaps.
From 2024 to 2025, emissions fell 22.3% while distance sailed fell 2.3%and CO₂ per nautical mile fell 20.5%.That points mainly to how efficiently it sailed, rather than the other.
Where the 2025 emissions occurred
Methane, nitrous oxide and EU ETS2025
- Total CO₂ equivalent
- 2,416 t
- Methane (CH₄)
- 0.04 t
- Nitrous oxide (N₂O)
- 0.14 t
- Under EU ETS
- 1,361 t, 57% of total
Verifier history
| From reporting year | Verifier | Accredited in |
|---|---|---|
| 2018 | Lloyd's Register Quality Assurance Ltd | United Kingdom |
| 2020 | Nippon Kaiji Kyokai | Japan |
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 2018–2025, published by the European Commission.
- Vessel particulars: Wikidata (CC0).
This page draws on 5 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.