ISDB — Internet Ship Database
Maritime Research & Analysis
Data-driven maritime research grounded in empirical AIS observations from 40,000+ vessels worldwide. Peer-quality analysis of fleet composition, vessel behaviour, trade patterns, and port activity.
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Port Quality Index: How a Port’s Operational Score Is Computed, with Singapore as Worked Example
A methods explainer for the ShipTracker Port Quality Index — the arithmetic mean of cached composite voyage scores across distinct vessels calling at a port in the last 30 days. Defines the index, derives it from the underlying voyage-analysis methodology, and walks through the worked example of Singapore (UN/LOCODE SGSIN), where 59 of 60 sampled vessels yield a quality reading of 49 against a global vessel-population median of about 50. Includes class-mix decomposition that explains why a high-volume mixed-class hub averages below 50 even though every individual ICCAS class median sits between 37 and 73, plus per-class contribution math, the methodology chain from raw AIS to port-level number, four worked-example port profiles, and explicit limits on what the index does and does not capture.
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Hardening the Voyage Analysis API: Drift Detection, Pool Pressure, and a Self-Serve Funnel
An engineering report from Phase 1 of the Voyage Analysis API. We built a JS↔Python parity harness that boots the JS engine inside Node’s
Read engineering reportvmsandbox and asserts byte-for-byte agreement with the Python port — and caught a real production bug on its first run, a falsy-zero check indetectLoitering()that had been silently undercounting every loiter event by exactly one position-report. We then ramped 200 concurrent calls at the live API to find the burst ceiling at ∼30 concurrent requests, and removed the founder from the funnel with a self-serve key-mint form at/api/signup. Includes pseudocode for the slicer, the recursive diff comparator, the atomic quota claim, and the signup handler — plus measured latency curves up to the 30 s handler timeout cliff. -
Anatomy of a Voyage: Inside the ShipTracker Voyage Analysis Tool, with OCEAN THUNDER as Worked Example
How the seven-component voyage performance score is computed: voyage detection from AIS tracks, route efficiency, CII estimation, speed profiling, loitering detection, port turnaround, course stability, the operational fingerprint radar, and the resistance-regime diagnostic. Includes the full pseudocode for the voyage segmentation algorithm, weighting tables, a worked example on OCEAN THUNDER’s 50-day Persian Gulf to Sungai Udang transit, and a counterfactual showing why fixed-window analytics return 38% route efficiency where voyage-window returns 96.9% on the same vessel.
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Navigating the Hormuz Crisis: AIS Intelligence, Maritime Safety, and Malaysia’s Energy Security
How real-time AIS vessel tracking transforms maritime risk management at the Strait of Hormuz — and why it matters for PETRONAS, Malaysian engineers, and Southeast Asia’s energy future. Includes live data: 360 tankers in the Gulf, average transit speed 7.7 knots, 1,039 tankers near Malaysia. Features an interactive Sankey of flag-registry-to-destination flows and a reconstructed voyage map of the OCEAN THUNDER crude corridor. Written for IEM Jurutera.
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OCEAN THUNDER: 60 Days on the Persian Gulf to Sungai Udang Crude Corridor
A 164,772 DWT Panama-flag Suezmax tanker bound for PETRONAS Penapisan Melaka. 839 AIS reports resolve into 41 days at central-Gulf anchorage during Iran’s declared closure of the Strait of Hormuz, an 11-day Indian Ocean transit through the US Navy counter-blockade window, and a three-day discharge at Sungai Udang during the peak of UANI-documented ghost-fleet activity in adjacent Malaysian waters. A single voyage shape, two readings.
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Global Shipping Lanes: Mapping the World’s Maritime Traffic
Thousands of AIS-tracked vessels rendered as glowing trails across a dark world map — revealing the arterial network of global trade. Fourteen days of position data processed through SeaPath coastline-aware interpolation, with interactive pan, zoom, vessel type filtering, and timeline playback.
Launch visualization -
North Sea Vessel Traffic: A 3D AIS Visualization of 5,214 Ships Over 14 Days
64,978 data points from 5,214 vessels — processed through SeaPath coastline-aware routing — rendered as glowing glowing particle trails in an interactive Three.js visualization. Watch cargo ships, tankers, and passenger ferries trace the Dover Strait, German Bight, and North Sea shipping lanes across fourteen days of maritime traffic.
Launch visualization -
10 Features That Set ShipTracker Apart: What You Won't Find on Other Maritime Platforms
From SeaPath coastline-aware routing to free nautical charts, a Voyage Analysis engine with Froude number and CII estimation, true real-time WebSocket push, and cinematic Showcase mode — ten proprietary capabilities that make ShipTracker different. With interactive demos.
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Four Map Layers for Maritime Intelligence: From Street Maps to Nautical Charts
ShipTracker provides four distinct map views — Default, Terrain, Satellite, and Nautical — each revealing different aspects of the maritime environment. Interactive side-by-side comparison of all four layers over Rotterdam, with OpenSeaMap seamark overlays showing buoys, lighthouses, and shipping lanes.
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SeaPath: Coastline-Aware Track Interpolation — Solving the AIS Gap Problem in Maritime Vessel Tracking
When AIS signals drop out, vessel tracks cut through land masses. SeaPath, our coastline-aware routing algorithm, detects gaps using Haversine analysis and fills them with waypoints routed around coastlines via a navigable waterway graph. Before-and-after demonstration with CONTSHIP ERA's 67-hour Mediterranean gap.
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Marine Traffic Risk Assessment: Rotterdam / Europoort Approaches — A Preliminary Report
A preliminary Marine Traffic Risk Assessment of the Rotterdam and Europoort approaches in the southern North Sea, covering 553,962 AIS positions from 4,588 unique vessels observed over 15 days. Vessel composition, speed distributions, dimensional analysis, navigational status, temporal patterns, flag state breakdown, draught analysis, and a traffic risk assessment with interactive Leaflet route maps and Chart.js visualisations.
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Voyage Analysis of 12 Commercial Vessels: Operational Speed Profiles and Froude Number Regimes from AIS Data
Per-vessel voyage analysis of 12 ships across five types—ferry, cargo, tanker, dredger—using 7,602 AIS positions over 15 days. 55.3% of all positions record vessels as idle. Froude number analysis shows all 12 vessels operate at Fn < 0.25 where viscous resistance dominates, with implications for multi-speed hull form optimisation.
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Chokepoint Atlas: Comparing Vessel Traffic Flows Across Five Maritime Straits
Five Sankey diagrams built from AIS data on 7,000+ vessels reveal how flag registries, fleet composition, and destination patterns diverge across the Strait of Malacca, Strait of Hormuz, English Channel, Hong Kong approaches, and Danish Straits. Each chokepoint has a unique traffic signature shaped by its economic function.
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Who Sails the Malacca Strait? A Visual Anatomy of 3,000 Vessels, Their Flags, and Their Destinations
A three-layer Sankey diagram of 3,100+ AIS-observed vessels reveals how open registries, vessel specialisation, and destination economics shape traffic through the world’s busiest waterway. Singapore, Panama, and Liberia flags account for 42% of traffic; tankers dominate the fleet bound for the Persian Gulf and “For Orders” assignments.
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Port Intelligence: Daily Trade Activity, Vessel Mix, and Cargo Flows Across 597 Global Ports
ShipTracker now tracks daily port calls, import/export volumes, and vessel mix across 597 ports worldwide. 168,000 daily activity records reveal that Singapore leads with 44,376 registered vessels, Asia dominates with 45% of all port activity, and tankers account for 59% of the global vessel fleet at anchor. Individual port pages deliver 90-day trade trends, fleet composition breakdowns, and cargo flow analysis.
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Strait of Hormuz: 978 Vessels and 342 Tankers Observed at the World’s Most Critical Oil Chokepoint
48-hour AIS snapshot of the Hormuz Strait reveals 342 tanker-class vessels (35% of traffic), a Fujairah anchorage holding 158 stationary ships at 90.3% anchor rate, and Panama/Liberia flags accounting for 24% of all tonnage. Greek-flagged crude oil tankers cluster at the Fujairah roadstead awaiting orders.
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Vessel Operational Fingerprints: Multi-Dimensional Radar Analysis of AIS Voyage Behaviour Across 50,061 Ships
Spider-web profiling of 8 vessel types across 6 operational dimensions reveals unique “operational DNA” per fleet segment. Bulk Carriers are underway 76.5% of the time while Pleasure Craft sit idle 98.5%. Open-registry fleets are 2.1× more active than traditional flags. Interactive Chart.js radar charts visualise the fingerprints.
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AIS Data Completeness: A Quantitative Assessment of 49,438 Vessel Records Across Ten Critical Fields
Only 3.8% of 49,438 AIS-tracked vessels report all ten critical fields. We measure per-field missing rates across IMO, call sign, ship type, destination, ETA, dimensions, and draught — revealing that dimensional data is absent in 60–65% of records while IMO numbers are missing for 45.5%. Flag-state analysis shows completeness rates ranging from 23% (Netherlands) to 89% (Liberia).
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Tracking NACHOS: An Aframax Tanker's 3,200-Nautical-Mile Voyage from the Atlantic to the Gulf of Finland
We reconstruct the complete voyage of the Tanzania-flagged Aframax tanker NACHOS (104,611 DWT) from the Atlantic coast of Portugal to Gogland Island in the Gulf of Finland — 3,200 NM across five maritime zones over eight days, using 217 AIS position records. Speed profiles, course analysis, and a 10-hour anchorage near Gogland reveal the anatomy of a long-haul tanker transit.
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Measuring Voyage Efficiency: A Multi-Criteria Scoring Framework for AIS-Derived Vessel Performance
Single metrics like speed or fuel consumption fail to capture voyage quality. We present a Weighted Sum Model combining seven AIS-derived indicators — route efficiency, CII compliance, speed consistency, loitering events, port call punctuality, course stability, and distance-to-time ratio — into a composite 0–100 score. Three vessel case studies illustrate scores ranging from 58 to 82.
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The Malacca Strait Bottleneck: Vessel Traffic Density and Transit Patterns in the World's Busiest Shipping Lane
Approximately 94,000 vessels transit the Straits of Malacca annually, carrying ~30% of global trade. We examine vessel type distribution, speed profiles, and chokepoint congestion between One Fathom Bank, Philip Channel, and the Singapore Strait using AIS position data from the region.
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Maritime Vessel Activity Patterns: An Empirical Analysis of 3.4 Million AIS Position Reports
77.4% of AIS reports correspond to stationary vessels. The top 10% of ships generate 37.8% of all position data. Rotterdam leads all destinations with 450 declared vessels. We examine activity states, Pareto-distributed reporting, tonnage concentration among VLCC tankers and ultra-large container ships, and the structural dominance of Northern European ports in a five-day global AIS dataset.
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Sailing FOR ORDERS: What 199 Vessels Without Fixed Destinations Reveal About the Spot Freight Market
199 vessels in the global AIS dataset declare "FOR ORDERS" as their destination — sailing without a fixed port, awaiting charterer instructions. 80% of identified types are tankers. Average length 231.8 m. We examine what this floating spot-market inventory reveals about freight economics, contango, and LNG oversupply.
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Still Sailing at 102: Vessel Longevity and the Oldest Active Ships in Global AIS Data
The oldest AIS-transmitting vessel in our dataset was built in 1924 — the Dutch sailing vessel REMBRANDT VAN RIJN, still active in Vlissingen at 102 years old. From 901 vessels with build-year data, we analyse fleet age distribution (mean 2009, σ = 11.6 years), survivorship patterns, and what keeps pre-1970 ships operational decades beyond their design life.
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The Dutch Fleet: 5,955 Vessels and Europe's Largest Inland Maritime Network
The Netherlands registers 5,955 AIS-equipped vessels — 14.7% of the global observed fleet and more than any other flag state. 97.2% are under 135 m, consistent with inland waterway dimensions. Amsterdam (239 vessels) and Rotterdam (194) lead destinations, but Harlingen, Dordrecht, Nijmegen, and Zwolle reveal the depth of the Dutch canal network.
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Flags of Convenience: How 17% of Vessels Carry 66% of Global Deadweight Tonnage
Open registries account for just 8,211 of 46,463 AIS-tracked vessels (17.7%), yet carry 80.98 million DWT — 65.7% of all observed deadweight tonnage. We examine the tonnage paradox, vessel type specialisation by flag (Liberia for tankers, Bahamas for cruise ships), and the mega-vessel club where every 400m ship flies either an open registry or a maritime hub flag.
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