Oil tanker · Marshall Islands flag · built 2008
CHRYSTAL SKY
IMO 9334569 EU ETS5 reporting years
- CO₂ reported 2024
- 3,290 t
- Fuel burned
- 1,037 t
- Time at sea
- 732 h
- Emitted at berth
- 12% of total
- Share of year under way
- 8%
- Gross tonnage
- 40,865
Vessel particulars
- IMO number
- 9334569
- Previously reported as
- POLAR UNICORN
- Ship type
- Oil tanker
- Gross tonnage
- 40,865
- Length overall
- 229.0 m
- Year built
- 2008
- Flag state
- Marshall Islands
- Builder
- Onomichi Dockyard
- Port of registry
- Majuro, Marshall Islands
- Home port
- Majuro, Marshall Islands
- Ice class
- IA
- Technical efficiency (design)
- EIV (4.03 gCO₂/t·nm)
- Verifier
- NORMEC VERIFAVIA SAS, France
- Accreditation
- 3-2127
- Compliance document issued
- 2025-06-05
- Compliance document expires
- 2026-06-30
Flag state is derived from rapportert, not reported directly, and reflects the registry at the time of reporting.
Efficiency against its own type2022
Position 579 of 1,771 qualifying oil tankers by EEOI, at the 33th percentile. The dashed line is the type median, 8.0; this vessel reported 6.5.
EEOI divides emissions by transport work, which for this vessel and year was 280,762,997 tonn-nmover 4,906 nautical miles.
Reported CO₂ by year
Between 2018 and 2024 reported CO₂ fell by 5.5%. No return is recorded for 2020, 2023, so the series has gaps.
From 2022 to 2024, emissions rose 79.2% and CO₂ per nautical mile rose 4.1%.Distance was not reported for both years, so activity and efficiency cannot be separated here.
Annual returns2018–2024
| Year | CO₂ (t) | Fuel (t) | Distance (nm) | At sea (h) | At berth (t) | kg CO₂/nm | EEOI | Percentile |
|---|---|---|---|---|---|---|---|---|
| 2024 | 3,290 | 1,037 | — | 732 | 381 | 389.7 | — | — |
| 2022 | 1,836 | 579 | 4,906 | 437 | 27 | 374.3 | 6.5 | 33 |
| 2021 | 16,872 | 5,415 | 37,901 | 3,192 | 105 | 445.2 | 9.0 | 56 |
| 2019 | 5,709 | 1,824 | 11,460 | 2,008 | 330 | 498.2 | 8.5 | 50 |
| 2018 | 3,481 | 1,116 | 9,812 | 1,126 | 106 | 354.8 | 9.4 | 58 |
Where the 2024 emissions occurred
Methane, nitrous oxide and EU ETS2024
- Total CO₂ equivalent
- 3,341 t
- Methane (CH₄)
- 0.05 t
- Nitrous oxide (N₂O)
- 0.19 t
- Under EU ETS
- 1,948 t, 59% of total
Verifier history
| From reporting year | Verifier | Accredited in |
|---|---|---|
| 2018 | AMERICAN BUREAU OF SHIPPING HELLENIC SINGLE MEMBER LIMITED LIABILITY COMPANY (ABS HELLENIC S.M. LTD) | Greece |
| 2022 | Korean Register | Korea, Republic of |
| 2024 | NORMEC VERIFAVIA SAS | France |
A change of accredited verifier is shown because it matters for audit and data continuity. It is not in itself a sign of anything being wrong.
Sources and how to read this
- Emissions: EU MRV publication (THETIS-MRV), reporting years 2018–2024, published by the European Commission.
- Vessel particulars: Wikidata (CC0).
What this page is built on
- Reporting years
- 5
- Ranked by efficiency
- yes
- Vessel particulars
- 5 of 5
- Movement data
- not observed
- Name history
- yes
- Photograph
- none licensed
- Sanctions record
- none
- Inspection record
- none in US waters
Caveats that apply to every vessel page
EEOI above 100,000 is withheld. Those values come from returns where reported transport work is near zero, which makes the ratio meaningless rather than extreme. Median across the dataset is around 12.
Emission categories overlap. In the MRV return, emissions at berth are also counted inside the voyage legs, so the categories do not sum to the total. They are shown side by side rather than stacked for that reason.
Distance is derived, intensity is reported. The MRV return publishes CO₂ per nautical mile but not the distance itself, which is null in all 106,564 rows of the source. The distance column is therefore filled from the ranking step, which reconstructs it, and is blank for years where a vessel was not ranked. That is why a row can show an intensity without a distance.
Percentile is within type and year. It is the vessel's position among qualifying ships of the same type that year, where lower is more efficient. A blank means the vessel did not qualify for ranking that year.
Sister ships share a builder, a type and a build year within two years of this vessel. That holds hull and machinery roughly constant and leaves operation as the variable, which is why they are listed before nearest-by-tonnage.
Methane and nitrous oxide start in 2024. They were not reported before that period, so earlier years cannot be compared against them.
Technical efficiency is a design figure fixed at construction. A vessel can hold a good index and still emit heavily by sailing fast, waiting at anchor or carrying little.
Inspection records cover United States waters only. An empty record is not evidence of a clean history elsewhere.
Empty means unreported, never zero. Nothing here is modelled, estimated or interpolated. See the methodology.
Something wrong on this page? See corrections. We do not hold the source registers and cannot amend them, but we will fix anything we have got wrong in reproducing them.