Maritime CII Compliance Dashboard
A learning project exploring IMO MARPOL Annex VI carbon intensity regulation through a real-time interactive dashboard.
What is this project
Section titled “What is this project”The International Maritime Organization (IMO) introduced the Carbon Intensity Indicator (CII) framework under MARPOL Annex VI to measure and rate the carbon efficiency of ships in commercial operation. Starting 2023, every qualifying vessel must be assigned an annual A–E rating based on how much CO₂ it emits per unit of transport work done.
This project is a self-built dashboard that implements the CII calculation methodology for a fictitious fleet of cruise ships, built entirely as a learning exercise to understand both the regulation and the tooling required to operationalise it.
What I learned
Section titled “What I learned”Regulatory side
Section titled “Regulatory side”- How CII is defined and calculated under MEPC.352(78) — the three metrics: cgDIST (mandatory), EEPI, and cbDIST (informational)
- How the reference line is set per MEPC.353(78) using vessel-class parameters a and c
- How annual required CII tightens each year under MEPC.400(83), rising from a 5% reduction in 2023 to 21.5% by 2030
- How the A–E rating is determined from the attained-to-required ratio using d-vectors in MEPC.354(78)
- What the EU ETS phase-in means for cruise operators: 40% obligation in 2024, 70% in 2025, 100% from 2026
Technical side
Section titled “Technical side”- Building a multi-page analytical dashboard in Python using Streamlit
- Connecting to Google Sheets as a live data source via the published CSV API
- Computing CII metrics in pandas from raw fuel consumption data merged with vessel master data
- Building interactive Plotly charts (line trends, horizontal bars, donut pies, heatmaps, stacked bars) with custom dark themes
- Making every chart title an interactive popover that explains the formula, key variables, and what to look for
- Adding verification tables with a separate recalculated totals row — for single-vessel views, cgDIST/cbDIST/EEPI are recalculated from the summed CO₂ and distances rather than just displayed
- Sidebar filters for year, month, owner, vessel, and fuel type
- Deploying to Streamlit Community Cloud via GitHub
Key features of the dashboard
Section titled “Key features of the dashboard”Fleet Overview
Section titled “Fleet Overview”Monthly cgDIST and cbDIST trends for all vessels side by side, a CII League table with colour-coded A–E ratings and a required-CII marker, a rating distribution donut, and a CO₂ heatmap across vessels and months.
Vessel Analytics
Section titled “Vessel Analytics”Drill into any vessel: monthly cgDIST vs the required threshold, fuel mix pie, monthly CO₂ bar, year-over-year CII performance with the tightening required line, and monthly and annual cbDIST trends.
Fuel & Emissions
Section titled “Fuel & Emissions”Stacked monthly fuel consumption by type, CO₂ ranking by vessel, fleet-average emission factor trend, and owner-group comparison where multiple operators are present.
CII Compliance
Section titled “CII Compliance”Annual A–E rating matrix across all vessels and years, attained vs required side-by-side bar chart, and a full verification table showing every step of the calculation.
EU ETS Impact
Section titled “EU ETS Impact”Estimated financial exposure per vessel based on the EU ETS phase-in schedule and an illustrative EUA price.
Data Explorer
Section titled “Data Explorer”Full raw and calculated dataset with all derived fields, downloadable as CSV.
Technology stack
Section titled “Technology stack”| Layer | Tool |
|---|---|
| Dashboard framework | Python · Streamlit |
| Data visualisation | Plotly (Express + Graph Objects) |
| Data processing | pandas · NumPy |
| Data source | Google Sheets (published CSV) |
| Deployment | Streamlit Community Cloud |
| Version control | Git · GitHub |
Live dashboard
Section titled “Live dashboard”The app is deployed on Streamlit Community Cloud. You can interact with by opening it directly in a new tab.
Regulatory references
Section titled “Regulatory references”- MEPC.352(78) — Guidelines on the method of calculation of the attained CII and required CII
- MEPC.353(78) — Guidelines on the reference lines for use with the CII
- MEPC.354(78) — Guidelines on the operational CII rating of ships (A–E rating)
- MEPC.355(78) — 2022 Interim guidelines on correction factors and voyage adjustments for CII calculations (not implemented in this tool)
- MEPC.400(83) — 2025 Guidelines on the reduction factors for the required CII (replaces earlier MEPC.338/377)