IMO DCS FAQs: Everything You Need to Know About the Ship Data Collection System

IMO DCS — formally the Ship Fuel Oil Consumption Data Collection System — was established under MARPOL Annex VI Regulation 22A, which became effective on 1 March 2018. Data collection for the first full calendar year commenced on 1 January 2019. It requires ships of 5,000 GT and above to collect, report, and verify fuel oil consumption data annually.

All fuel oils consumed on board the ship must be reported, categorized by fuel type. Recognized fuel types include Heavy Fuel Oil (HFO), Light Fuel Oil (LFO), Marine Gas Oil (MGO), Marine Diesel Oil (MDO), Liquefied Natural Gas (LNG), Liquefied Petroleum Gas (LPG), methanol, ethanol, and other fuel types as recognized by the IMO. Each fuel type has a specific CO2 conversion factor applied during reporting.

The mandatory data parameters are: fuel oil consumption (in metric tonnes, by fuel type), distance travelled (in nautical miles), hours underway, and transport work (cargo carried multiplied by distance) where the ship is able to collect this data. Ships that cannot collect transport work data must record the reason and submit without it, though transport work data is strongly encouraged as it enables more meaningful efficiency analysis.

The annual data collected under IMO DCS must be verified by an approved verifier before it is submitted to the flag state. Approved verifiers include recognized organizations (class societies) and other bodies authorized by administrations. The verifier reviews the data collection methodology, checks for completeness and plausibility, and issues a verification statement. Without a verification statement, the flag state will not issue a Statement of Compliance.

The Statement of Compliance is the document issued by the flag state administration confirming that the ship has met its IMO DCS data collection and reporting obligations for the relevant calendar year. The SoC must be carried on board and is subject to inspection at port state control. Ships that fail to obtain a valid SoC may face port state control deficiencies.

IMO DCS data forms the input for CII calculation. The fuel consumption and distance data collected under IMO DCS, once aggregated at the annual level and combined with ship capacity data, produce the Attained CII. Because the same underlying data serves both purposes, having accurate and complete IMO DCS data is a prerequisite for accurate CII calculations. Inconsistencies in IMO DCS data will propagate into CII ratings.

Flag states are required to take action against ships that fail to comply with IMO DCS requirements. Consequences vary by flag state but can include withholding of the Statement of Compliance, port state control deficiencies, detention in port, and in some cases fines. Given that the SoC is increasingly required by charterers and commercial counterparties, non-compliance also carries direct commercial consequences.

Amendments to submitted IMO DCS data are possible but must go through the flag state administration and verifier. The process varies by flag state, but typically involves a revised data submission with a new or updated verification statement. Given the administrative burden of post-submission amendments, investing in data quality at the collection stage is far more efficient.

Ecosail's IMO DCS module automates data collection from noon reports, BDNs, and sensor feeds; applies correct emission factors; generates the annual data report in flag-state-compatible formats; manages the verifier workflow; and archives all compliance records. Fleet managers gain real-time visibility into each vessel's data completeness, and automated alerts ensure submission deadlines are never missed. Contact Ecosail to learn how our platform can eliminate manual IMO DCS processes from your fleet operations.