Neptune Atlas

Bunkers

Emission control areas

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An emission control area is a piece of sea where the fuel a ship may burn is capped tighter than it is everywhere else. It changes nothing about the route, nothing about the cargo and nothing about the ship’s speed. What it changes is which grade comes out of which tank, and since the two grades are priced differently, a voyage that spends a week inside one has a bunker bill that a voyage of the same length outside does not.

What the limit actually is

Under MARPOL Annex VI the sulphur content of fuel oil used on board is capped at 0.50% by mass worldwide. Inside a designated emission control area the cap is 0.10%. That has been the level in every established area since 1 January 2015, and it is the number the trade means when it says a voyage is “in the ECA”.

There are two ways to satisfy it. The ordinary one is to burn a compliant fuel: a distillate, usually low sulphur marine gas oil, in place of the heavier residual grade the main engine burns at sea. The other is an approved equivalent, in practice an exhaust gas cleaning system, which lets a ship go on burning high sulphur fuel and clean the exhaust instead. Which of the two a particular hull uses is a fact about that hull and it decides whether the area costs her anything at all.

Where they are

Ten areas, and they are not one thing. Three are enclosed or semi-enclosed seas whose boundaries are written as lines of latitude and longitude. Four are offsets from a North American coastline. Three were designated recently and are not yet a cost, which is the part most often got wrong.

AreaWhat it controlsThe date that matters
Baltic SeaSulphur, and Tier III nitrogen oxides for keels laid on or after 1 January 2021In force since 2006, at 0.10% since 2015
North Sea and English ChannelSulphur, and Tier III for keels from 1 January 2021In force since 2007, at 0.10% since 2015
North American, Atlantic and Gulf of MexicoSulphur, and Tier III for keels from 1 January 20161 August 2012
North American, PacificAs above1 August 2012
North American, HawaiiAs above1 August 2012
United States Caribbean SeaAs above1 January 2014
Mediterranean SeaSulphur and particulate matter only. No nitrogen oxide requirement at all1 May 2025
Canadian ArcticSulphur and Tier IIIIn force 1 March 2026. Fuel requirement from 1 March 2027
Norwegian SeaSulphur and Tier IIIIn force 1 March 2026. Fuel requirement from 1 March 2027
North-East AtlanticSulphur and Tier IIIIn force 1 September 2027. Fuel requirement from 1 September 2028

A designated area is not yet a cost

Read the last three rows again, because this is where estimates go wrong in both directions at once.

The Canadian Arctic and the Norwegian Sea became emission control areas on 1 March 2026. The 0.10% fuel requirement in them does not begin until a year later. An estimate written today for a voyage next month that charges distillate for the Norwegian Sea has invented a cost, and the broker who did it will lose the cargo to somebody who did not.

The North-East Atlantic is the larger one and it runs the other way. It covers the water off Ireland, the United Kingdom, France, Spain, Portugal, the Faroes, Iceland and Greenland, with the Azores, Madeira and the Canaries included separately. That is most of the Atlantic side of the European trades. It enters into force on 1 September 2027 and the fuel requirement follows on 1 September 2028. A voyage being quoted now for 2028 is being quoted as though that water were free, and it will not be.

So an area has a date, and an estimate is priced against a date rather than against a map. The two mistakes are one line apart and only one of them is visible on a screen.

Designated, not yet costly

Three of the ten areas exist today and cost nothing today. The field that prices a voyage is the date the fuel requirement applies, not the date the area was designated. On all three the gap between the two dates is a year, and every one of those years is full of fixtures somebody has to quote.

The boundaries, and which of them are real lines

Some of these boundaries are exact and some are approximations, and it is worth knowing which you are standing on.

The enclosed seas are written as lines. The Baltic stops at the parallel of the Skaw, 57°44.8’N, taken across the entrance in the Skagerrak: south and east of it is Baltic. The North Sea area stops at 62°N to the north and 4°W to the west, and its Channel corner is at 48°30’N and 5°W. The Mediterranean stops at 5°36’W in the Strait of Gibraltar and at the 41st parallel at the Turkish straits. Those are the regulation’s own coordinates and there is nothing to interpret.

The North American and United States Caribbean areas are different in kind. They are a 200 nautical mile offset from a baseline, which is a curve, and the regulation defines it with about a hundred and thirty published coordinates. Anything that draws that shape approximately is approximate, and a route measured against it is accurate to tens of miles rather than to the mile.

Two consequences follow that a broker meets in practice. The Irish Sea and the Celtic Sea are outside the North Sea area, because the regulation’s western limit runs down 5°W to the Cornish coast rather than around Ireland. They stay outside until the North-East Atlantic area begins, and then they are inside. And the Black Sea is not an emission control area at all, while the Sea of Marmara south of 41°N is, so a ship coming down from Novorossiysk crosses into one part way through the Turkish straits.

Nitrogen oxides are a different control on a different thing

The sulphur limit is about the fuel in the tank, so it applies to every ship that enters the area. Tier III nitrogen oxide control is about the engine, and it catches a ship according to when her keel was laid or her building contract was signed. It is therefore a fact about the hull rather than about the voyage: an older ship is not caught at all, and a newer one had to be built for it. Nothing about it changes what this voyage burns.

The dates differ by area and they are not intuitive. North American waters catch keels laid from 1 January 2016; the Baltic and North Sea catch keels from 1 January 2021; the Canadian Arctic catches keels from 1 January 2025; the Mediterranean has no nitrogen oxide requirement whatever. For chartering purposes the practical point is short: sulphur is a cost on this voyage, nitrogen oxide is a question about how a particular hull was built, and the answer to the second is on her certificates rather than in a table.

What it does to an estimate

The switch comes off one line and not off the whole bunker bill. At sea a ship burns the heavy grade in her main engine and a distillate in her auxiliaries and boiler. Inside an emission control area it is the main engine that changes grade; the auxiliaries were already burning the distillate and nothing about them moves. So the miles inside the area convert a slice of the heavy tonnage to the distillate price, and an estimate that reprices the entire day has double counted.

Which trades this actually bites on is worth knowing before the estimate is opened. Since May 2025 the whole Mediterranean is an area, so a ship coming up from Suez burns the distillate for every mile from the canal to Gibraltar. That single change put a long stretch of controlled water in the middle of the Gulf and Asia to north-west Europe trades, where before there was none between the Red Sea and the Channel.

Who carries it depends on the charter. Under a voyage charter the owner buys the bunkers, so the area is the owner’s cost and it belongs in the freight. Under a time charter the charterer buys them, so it is the charterer’s cost, and what the owner owes is a ship that can actually burn the compliant grade and the certificates to prove it.

Steaming round one, and when that is a fantasy

Because the areas are geography, the obvious question is whether a ship can keep out of one. Sometimes she can. The North American area reaches offshore, so a ship coasting between two United States ports may find that standing out to sea and coming back in saves more distillate than the extra distance costs. That is a real trade-off and it is worth running both ways.

Often she cannot, and what decides it is how deep inside the area she is rather than how far the nearest line is. The North Sea area is hundreds of miles across in every direction that matters, so a ship at Rotterdam is not near a usable edge of it at all. A ship loading in the Baltic has exactly one way out, the Skaw, several hundred miles away, and taking it is not a bypass but the voyage. The Mediterranean is the same shape. Asking whether to avoid an area whose berth you are loading at is not a question, and software that answers it with a number has measured something other than the sea.

What none of this is

Everything above is a planning description of where the money goes. It is not a compliance tool. Boundaries move when the regulation is amended, several of these areas have exclusions and carve-outs that a rectangle or a traced ring will not hold, and the reporting and record-keeping obligations that go with a fuel changeover are a matter for the ship rather than for an estimating sheet. Confirm the boundary, the requirement and the paperwork against the current regulation and the flag state before anybody relies on it. What an estimate needs to know is how many miles are inside and what the grade costs, and that is a narrower question than compliance on purpose.

References

Bunkers and fuel gradesTwo grades and sometimes three, priced apart. The largest number on a voyage estimate is also the one nobody warrants. Time charter equivalentFreight per tonne means nothing next to hire per day until you divide it by the voyage. This is the arithmetic that does it. Voyage charter vs time charterThe risk split behind the two main charter forms, what each side pays for, and which terms only exist on one side of it.

Neptune Atlas

Neptune Atlas measures how many miles of a drawn route fall inside each area and returns the total as days of distillate on the estimate, so the switch is priced instead of typed. The boundaries are planning approximations of the published areas, each one carrying how it was drawn, and the product says so on every answer rather than presenting them as the regulation. Every paid plan starts with 7 free days. A card is needed to start them, and cancelling before they end costs nothing.

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