Chemical tanker · Portugal flag · built 2021
FRONA: CO₂ emissions 2022–2025
IMO 9585481 EU ETS4 reporting years
- CO₂ reported 2025
- 460 t
- Fuel burned
- 152 t
- Time at sea
- 272 h
- Emitted at berth
- 70% of total
- Share of year under way
- 3%
- Gross tonnage
- 6,247
FRONA against its type
Built in 2021, it is 11 years newer than the median chemical tanker on this register, which was built in 2010 (1,951 vessels with a known build year). At 6,247 gross tonnage it is smaller than 93% of the other 1,899 chemical tankers with a recorded tonnage. It is one of 71 chemical tankers here under the Portugal flag, 3.0% of the 2,344 on the register. Its MRV returns name it FRONA for 2022 and HERCULES SKY for 2023–2025. The reported port of registry changed: Panama (2022), then Madeira (2023–2025).
Its 460 t of CO₂ for 2025 is 92% below the median of 5,533 t among the 1,483 chemical tankers on this register that reported for 2025. Per nautical mile it emitted 534.1 kg CO₂, 2.1 times the type median of 250.2 kg. It logged 272 hours at sea against a median of 2,109 hours for its type that year. 69.8% of its 2025 emissions were at berth; the median for chemical tankers was 6.6%. Across 4 years with reported emissions, the highest was 2022 (2,822 t) and the lowest 2025 (460 t). Of the 6 comparable vessels listed below with a 2025 return, 6 reported a lower CO₂ per nautical mile than this vessel.
Emissions by year2022–2025
| Year | CO₂ (t) | Fuel (t) | Distance (nm) | At sea (h) | At berth (t) | kg CO₂/nm | EEOI | Percentile |
|---|---|---|---|---|---|---|---|---|
| 2025 | 460 | 152 | — | 272 | 321 | 534.1 | 138.9 | not ranked |
| 2024 | 844 | 263 | — | 517 | 521 | 339.1 | 73.6 | not ranked |
| 2023 | 520 | 162 | — | 271 | 297 | 890.8 | 229.8 | not ranked |
| 2022 | 2,822 | 880 | 19,671 | 2,945 | 180 | 143.4 | 41.4 | 93 |
Vessel particulars
- IMO number
- 9585481
- Previously reported as
- HERCULES SKY
- Ship type
- Chemical tanker
- Gross tonnage
- 6,247
- Length overall
- 118.0 m
- Beam
- 19.0 m
- Year built
- 2021
- Flag state
- Portugal per EU MRV 2025
Sources disagree: Wikidata/AIS (undated) list Panama. The flag shown is from the newest official source, the EU MRV return for 2025. - Port of registry
- Madeira MRV 2025
- Technical efficiency (design)
- EEDI (12.7 gCO₂/t·nm)
- Efficiency ranking
- Not ranked: distance below the floor (2025)
- Verifier
- Bureau Veritas Certification France, France
- Accreditation
- 3-2047 rev. 4
- Compliance document issued
- 2026-03-26
- Compliance document expires
- 2027-06-30
Reported CO₂ by year
Reported CO₂ in 2025 was 83.7% lower than in 2022, for EU/EEA voyages only.
From 2024 to 2025, emissions fell 45.5% and CO₂ per nautical mile rose 57.5%.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
- 468 t
- Methane (CH₄)
- 0.01 t
- Nitrous oxide (N₂O)
- 0.03 t
- Under EU ETS
- 392 t, 85% of total
Verifier history
| From reporting year | Verifier | Accredited in |
|---|---|---|
| 2022 | NORMEC VERIFAVIA SAS | France |
| 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 2022–2025, published by the European Commission.
- Vessel particulars: Wikidata (CC0).
This page draws on 4 MRV reporting years, 4 of 5 vessel particulars and a name history. Not found in the sources for this vessel: an efficiency ranking, 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.