1. Convoy Mode Concept
A convoy is a dynamic, GPS-relative grid of seasteads that maintain fixed positions relative to each other while the entire formation moves through the ocean. The system turns the fleet into a single distributed “night watch” with massive sensor coverage, redundancy, and collective intelligence.
Key Benefits
- Shared 360° maritime domain awareness using parallax from multiple precisely located platforms
- Collective AI + human watch standing (any qualified person on any vessel can stand watch for the fleet)
- Automatic collision avoidance and traffic deconfliction at fleet scale
- Plug-and-play joining/leaving: new seasteads are assigned a grid slot and handed off to autopilot
- Extremely low bandwidth command channel while maintaining high-bandwidth sensor sharing
2. Local Mesh Network Architecture
We recommend a hybrid WiFi 6 + directional mesh operating in the 5 GHz band, with an optional 60 GHz high-bandwidth backbone between nearest neighbors.
Primary Recommendation: WiFi 6 (802.11ax) Mesh – 5 GHz
| Item | Specification |
|---|
| Range (clear ocean line-of-sight) | ≈ 4–7 km (with high-gain directional antennas) |
| Practical convoy spacing | 500–1500 m (well within reliable link) |
| Typical throughput per link | 300–800 Mbps (real-world) |
| Cost per seastead (4× directional nodes) | $380–$650 |
Hardware Bill of Materials (per seastead)
- 4× Ubiquiti NanoBeam 5AC Gen2 or Rocket 5AC Prism (or equivalent WiFi 6 outdoor AP with 30–34 dBi gain directional antennas)
- 1× MikroTik RB4011 or equivalent router with 10 Gbps SFP+ for internal backbone
- Optional: 2–4× 60 GHz mmWave links (e.g. MikroTik Wireless Wire or Ubiquiti airFiber 60) for 1–2 Gbps inter-neighbor links
- 4× weatherproof PoE switches and surge protection
- Starlink Maritime antenna (already assumed) as primary long-haul backhaul
Antenna Layout: One directional panel or dish aimed at each of the four cardinal convoy neighbors (Forward, Aft, Port, Starboard). The triangle layout means each seastead will usually have two close neighbors on the “back” edge and one forward. Software automatically steers traffic via the best path.
3. Software & Protocol Stack
Core Components
- BATMAN-adv or OLSRv2 mesh routing (layer 2) – extremely robust at sea
- ZeroMQ + Protobuf for low-latency command & control messages
- ROS 2 (Robot Operating System) or custom DDS for sensor data distribution
- MAVLink extended for marine use (position, thruster commands, stabilizer setpoints)
- Custom Convoy Protocol (ConvoyLink) on top of the above
ConvoyLink Protocol Features
- Dynamic grid slot assignment & hand-off
- Relative position beacons at 10 Hz using Moving-Base RTK
- Watch-standing token system (cryptographic proof-of-attention)
- Distributed object database synchronization (AIS + visual + radar tracks)
- Parallax distance calculation service
- Emergency “break convoy” broadcast with collision-avoidance vectors
All vessels run identical open-source software stack (planned release under AGPL). Updates are pushed via Starlink when in range of land or via mesh from any vessel that has received them.
4. Convoy Mode Operational Flow
- Join Request: New seastead approaches from outside the formation, requests slot via Starlink or long-range radio. Convoy command node (any elected or rotating lead vessel) assigns optimal grid position based on wind, current, and formation shape.
- Approach Phase: Autopilot uses RTK relative positioning to close to within 0.5 grid spacing.
- Convoy Mode Activation: When relative position is stable for 30 seconds, all vessels acknowledge and the new unit is added to the mesh routing table and distributed object database.
- Steady State:
- Each platform publishes its RTK-relative position at 10–20 Hz
- All cameras, radars, and AIS feeds are fused into a shared maritime picture
- Any vessel can designate itself “On Watch.” A simple cryptographic challenge-response + periodic heartbeat confirms the human is present and alert.
- AI models (lightweight YOLOv8, custom maritime trackers) run on each vessel and share only high-confidence tracks to reduce bandwidth.
- Parallax Ranging: When multiple platforms see the same visual or radar contact, the system automatically computes 3D position using known baseline between seasteads. Accuracy improves dramatically with wider separation.
- Leave Convoy: Any vessel can request departure. The formation gently opens a gap or reshuffles using coordinated thruster commands.
5. Sensor Fusion & Collective Awareness
Each seastead contributes:
- 4K PTZ camera (starlight low-light) on roof
- Marine radar (optional but recommended – Furuno or Simrad)
- AIS receiver/transponder
- IR/thermal camera for night watch
- High-precision IMU + Moving-Base RTK GPS (u-blox or Septentrio)
All raw detections are timestamped with RTK time and published to the mesh. A distributed Kalman filter runs on multiple vessels simultaneously, producing a single shared “Fleet Maritime Picture” that is more accurate than any single platform could achieve.
6. Cost Estimate (Communications Only)
| Component | Unit Cost | Qty | Total |
|---|
| WiFi 6 Directional AP (NanoBeam 5AC or equivalent) | $110 | 4 | $440 |
| Router / Edge Compute (MikroTik RB5009 or similar) | $220 | 1 | $220 |
| 60 GHz backup link (pair) | $180 | 2 | $360 |
| Cabling, surge protection, mounts | $180 | 1 | $180 |
| Total per seastead | | | ≈ $1,200 |
This is a very modest addition to an already complex vessel. Using consumer/prosumer WiFi 6 gear keeps the cost low while still providing multi-kilometer range and hundreds of Mbps between neighbors — more than enough for sharing compressed video, radar tracks, and RTK corrections.
Additional Recommendations & Open Questions
- Redundant long-range backup: add a LoRa or HF packet radio mesh (very low bandwidth but works over 50+ km in emergencies).
- Cybersecurity: all mesh traffic encrypted with WireGuard tunnels between every pair of neighbors. Convoy command messages digitally signed.
- Human factors: “Watch Standing” app on tablets and phones. Simple interface showing current contacts, AI confidence, and a large “I Am Alert” button that must be pressed every 15–20 minutes when on duty.
- Formation shapes: default is hexagonal or square grid. Software can dynamically change spacing based on sea state (wider in high waves to reduce risk of collision).
- Legal: all vessels still transmit AIS as individual ships, but can also transmit a “convoy group” identifier on a dedicated channel.