> ## Documentation Index
> Fetch the complete documentation index at: https://www.worldmonitor.app/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Maritime Intelligence

> Real-time vessel tracking with chokepoint monitoring, traffic density analysis, dark ship detection, and WebSocket-based AIS data streaming.

The Ships layer provides real-time vessel tracking and maritime domain awareness through AIS (Automatic Identification System) data, monitoring critical chokepoints, detecting anomalous vessel behavior, and streaming position updates over WebSocket connections.

## Route Explorer

Route Explorer is the keyboard-first workflow for planning a shipment between any two countries and seeing chokepoint exposure, bypass corridors, land alternatives, and per-country impact — all on top of this maritime layer. See the dedicated [Route Explorer](/docs/route-explorer) page for the full workflow, tab contents, keyboard bindings, and tier gating.

## Chokepoint Monitoring

The system monitors the canonical strategic-waterway registry for disruptions that could affect global trade. It uses IMF PortWatch for weekly vessel transit counts, AISStream for the real-time crossing counter, and CorridorRisk for risk intelligence.

| Chokepoint | Strategic Importance |
| - | - |
| **Strait of Hormuz** | 20% of global oil transits; Iran control |
| **Suez Canal** | Europe-Asia shipping; single point of failure |
| **Strait of Malacca** | Primary Asia-Pacific oil route |
| **Bab el-Mandeb** | Red Sea access; Yemen/Houthi activity |
| **Panama Canal** | Americas east-west transit |
| **Taiwan Strait** | Semiconductor supply chain; PLA activity |
| **Cape of Good Hope** | Suez bypass route for VLCCs |
| **Strait of Gibraltar** | Atlantic-Mediterranean gateway; NATO chokepoint |
| **Bosporus Strait** | Black Sea access; includes Dardanelles corridor; Montreux Convention |
| **Korea Strait** | Japan-Korea trade; busiest East Asia corridor |
| **Dover Strait** | World's busiest shipping lane |
| **Kerch Strait** | Russia-controlled; Ukraine grain via Azov restricted |
| **Lombok Strait** | Malacca bypass for large tankers |

Each chokepoint card shows real-time transit counts (tanker vs cargo), week-over-week change, and an expandable 180-day time-series chart rendered with TradingView lightweight-charts.

## Density Analysis

Vessel positions are aggregated into a 2-degree grid to calculate traffic density. Each cell tracks:

* Current vessel count
* Historical baseline (30-minute rolling window)
* Change percentage from baseline

Density changes of +/-30% trigger alerts, indicating potential congestion, diversions, or blockades.

## Dark Ship Detection

The system monitors for AIS gaps, vessels that stop transmitting their position. An AIS gap exceeding 60 minutes in monitored regions may indicate:

* Sanctions evasion (ship-to-ship transfers)
* Illegal fishing
* Military activity
* Equipment failure

Vessels reappearing after gaps are flagged for the duration of the session.

### Backed by endpoints

| Surface | Endpoint | Notes |
| - | - | - |
| Vessel snapshot | `GET /api/maritime/v1/get-vessel-snapshot` | Civilian AIS point-in-time view for traffic and disruption context. |
| Navigational warnings | `GET /api/maritime/v1/list-navigational-warnings` | NGA maritime safety warnings used by chokepoint and undersea-cable awareness. |
| IMD port / sea / coastal | Bootstrap `imdCycloneMarine` (`weather:imd-cyclone-marine:v1`) | Official IMD port warnings and sea-area / coastal bulletins with issuing ACWC/CWC, valid times, wind, visibility, and sea state. Not merged into NWS weather alerts. Fishermen warning stays disabled (indexed, no field reference). |

## WebSocket Architecture

AIS data flows through a WebSocket relay for real-time updates without polling:

```
AISStream -> WebSocket Relay -> Browser
              (ws://relay)
```

The connection automatically reconnects on disconnection with a 30-second backoff. When the Ships layer is disabled, the WebSocket disconnects to conserve resources.

## Railway Relay Architecture

Some APIs block requests from cloud providers (Vercel, AWS, Cloudflare Workers). A [Railway relay server](/docs/relay-parameters) provides authenticated access:

```
Browser -> Railway Relay -> External APIs
           (Node.js)      (AIS, OpenSky, RSS)
```

**Relay Functions**:

| Endpoint | Purpose | Authentication |
| - | - | - |
| `/` (WebSocket) | AIS vessel stream | AISStream API key |
| `/opensky` | Military aircraft | OAuth2 Bearer token |
| `/rss` | Blocked RSS feeds | None (user-agent spoofing) |
| `/health` | Status check | None |

**Environment Variables** (Railway):

* `AISSTREAM_API_KEY` - AIS data access
* `OPENSKY_CLIENT_ID` - OAuth2 client ID
* `OPENSKY_CLIENT_SECRET` - OAuth2 client secret

**Why Railway?**

* Residential IP ranges (not blocked like cloud providers)
* WebSocket support for persistent connections
* Global edge deployment for low latency
* Free tier sufficient for moderate traffic

The relay is stateless; it simply authenticates and proxies requests. All caching and processing happens client-side or in Vercel Edge Functions.

See also [Finance Data - Chokepoints](/docs/finance-data) for disruption scoring methodology.