Every AIS transmission is a vote for where a ship goes — and accumulated over years and billions of positions, those votes draw the ocean's real road map. Not the charted routes, but the sailed ones: the lanes traffic actually follows, season by season, vessel type by vessel type.

A model trained on that history learns the normal — and therefore can do two things a chart can't: predict where a ship is probably going, and flag the ship that isn't going where a ship like it should be going.

Key findings

  1. AIS history is the largest behavioural dataset of shipping — the foundation for learned route prediction. Established
  2. The model's output is probabilistic — a distribution over likely destinations and routes, not a single prediction. Established
  3. Prediction powers two applications: anticipatory analytics (ETA, traffic forecasting) and anomaly detection (the vessel off-pattern). Established
  4. AIS data is corrupted by spoofing, gaps, and errors — the model learns the noise as well as the signal. Established
  5. The hard evaluation is the unusual case — the model is best on the common routes, worst where the data is thin. Maritime-GPT analysis
AIS traffic density map
The shipping lanes aren't drawn on the ocean — they're drawn by the accumulated tracks of every ship that reported them.Image: John H Darch · CC BY-SA 2.0

What the data actually teaches

An AIS-trained model learns the statistical geography of shipping — which lanes vessels prefer by type and season, how they approach ports, where they anchor, how they route around weather. The prediction isn't 'this ship will go to Singapore' — it's a probability distribution over destinations and routes conditioned on the track so far. The model's competence is the traffic pattern's competence: strong where shipping is regular, thin where it's rare. Established

Two uses, one model

  • <strong>Anticipation.</strong> Predicting ETAs, traffic density, port congestion — the forward view that powers scheduling. Established
  • <strong>Anomaly.</strong> Flagging the vessel whose track doesn't match the pattern its type should follow — the dark-fleet, smuggling, or distress signature. Established
  • <strong>Context.</strong> Feeding the route-probability estimate into other systems — the collision model, the port twin, the surveillance stack. Maritime-GPT analysis

The data-quality floor

AIS is a self-reported system — positions can be wrong, fields corrupted, and entire tracks falsified by spoofing or silent switching. A model trained on the raw stream learns the noise as well as the signal, and the anomaly detection it produces inherits the same confusion: a 'suspicious' track may be a transmitter fault, not a dark fleet. The honest model treats data-quality filtering as a preprocessing layer, not an assumption. Established

The evaluation honesty

Route prediction papers report accuracy averaged over all tracks — which mostly measures performance on the common routes the model already knows. The cases that matter (the unusual voyage, the diverted ship, the vessel off-pattern) are precisely where the data is thin and the accuracy is worst. The honest benchmark is per-case: how well does it predict the route that isn't the modal one? A model that's 95% right on the average ship may be useless on the ship that's actually interesting. Maritime-GPT analysis

What we know

  • AIS history is the foundation dataset for learned route prediction.
  • The output is a probability distribution over destinations/routes, not a point estimate.
  • Data quality — spoofing, gaps, errors — is a preprocessing problem, not an edge case.

What we don't

  • How well prediction holds on rare routes where data is sparse.
  • Whether anomaly detection based on AIS can distinguish spoofing from malfunction.
  • The model's behaviour under deliberate AIS manipulation.

Being tested

  • Per-case accuracy benchmarks on unusual voyages.
  • Spoofing-robust anomaly scoring.
  • Route-prediction integration into traffic-forecast systems.

Maritime-GPT analysis

AIS-trained prediction is maritime AI's most honest dataset problem — the data is real, the patterns are real, and so is the noise. The model learns where ships go and can spot the one that doesn't belong — but only where the data is thick. The confidence interval matters more than the point estimate: the model that admits which routes it doesn't know is the one worth trusting on the ones it does. Maritime-GPT analysis

This is a research feature, not operational guidance. Simulation results are reported as simulation; demonstrations are not deployments; company claims are attributed as such. Verify safety-critical decisions against official nautical publications and flag-state requirements.

Sources & evidence

Maritime-GPTCompanion research
AIS + SAR + optical surveillance

The satellite stack that uses AIS-anomaly as its signal.

Maritime-GPTCompanion research
AIS spoofing and GNSS attacks

The data-corruption problem the prediction model inherits.

Maritime-GPTCompanion research
AI ETA prediction

The anticipatory application the route prediction feeds.

Maritime-GPTCompanion research
Multimodal maritime AI

AIS as one modality in the fused picture.