SeaMark combines decades-proven passive magnetometry with modern low-cost MEMS sensors and an intuitive smartphone app. No invention required — only integration.
The challenge specifies saltwater, thermoclines, and 5–30m depth. These constraints eliminate most detection methods.
| Method | Saltwater | Thermoclines | Buried EO | Non-Expert | <$5K | Safe for UXO |
|---|---|---|---|---|---|---|
| Passive magnetometry | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ Zero emission |
| Active sonar | ✓ | ✗ Refracted | ✗ | ✗ Expert imagery | ✗ $8K–50K+ | ✗ Emits energy |
| EMI (metal detector) | ✗ Attenuated | ✓ | ✓ | ✓ | ✓ | ✗ Emits EM field |
| Chemical sensors | ✗ Diluted | ✓ | ✗ | ✗ | ✗ | ✓ |
| Trained animals | ✓ | ✓ | ✗ | ✗ | ✗ | ✓ |
Two people, one boat, half-day training. Here's the full operational cycle.
Clamp the surface electronics box to the boat's gunwale. Connect the tow cable and lower the towfish over the stern. Power on — the LED turns green when sensors are linked. Open the SeaMark app and confirm GPS lock.
The app runs an automatic boat-compensation routine: a brief static hold followed by a slow 360° turn. This cancels the vessel's own magnetic signature. Done once per survey day.
Drive at 2–4 knots along transect lines shown on the app. One person drives, the other monitors. The towfish sensors measure magnetic field distortions continuously. A depth sensor reports towfish altitude above the seabed in real time.
When the gradient exceeds threshold: audio tone + vibration + screen flashes red. A GPS waypoint is auto-dropped. The operator taps "Confirm" or "Dismiss." Optionally deploy a physical marker buoy 20 meters offset for visual warning.
Connect to WiFi or cellular. The app uploads the survey track and all waypoints to the Marine Hazard Atlas. Data exports as GPX, KML, GeoJSON, and CSV — compatible with Garmin GPS, Google Earth, QGIS, and IMSMA.
The Atlas aggregates detections into geofenced hazard zones visible to anyone with a phone or browser. Clusters are classified by density. NGOs and mine action authorities plan clearance using the same data.
1.2m PVC tube housing two MEMS fluxgate magnetometers in a vertical gradiometer arrangement, plus a depth sensor. Non-magnetic construction. Towed 10–20m behind the boat on a Kevlar-reinforced cable.
Gunwale-mounted box with ESP32 microcontroller, Bluetooth relay to smartphone, and LiFePO4 battery providing 50+ hours runtime. Rechargeable via any 20W solar panel.
Android & iOS app with real-time color-coded magnetic display, automatic anomaly detection, GPS waypoint marking, survey tracking, and offline-first architecture. Exports to all standard GIS formats.
Open-data web platform aggregating all survey data into cumulative hazard maps. Supports IMSMA, HDX, WFS/WMS integration. Accessible via any web browser at no cost.
Well under the $5,000 CAPEX ceiling. Two configurations available.
Annual OPEX: $40–360. Primarily optional cellular data for cloud sync. Zero fuel costs. Solar rechargeable. No consumables.
Conservative estimates based on published magnetic dipole models and field data.
| Ordnance Type | Ferrous Mass | Detection Range | Notes |
|---|---|---|---|
| 81mm mortar | ~3 kg | 5–8 m | Challenge minimum target |
| 105mm artillery shell | ~8–12 kg | 8–15 m | Standard artillery round |
| 250 lb aerial bomb (WWII) | ~50–70 kg | 15–25 m | Common legacy ordnance |
| 500 lb aerial bomb (WWII) | ~100–140 kg | 20–35 m | Exceeds 30m target depth |
| Sea mine | ~80–200 kg | 20–40+ m | Very large magnetic anomaly |
| Torpedo (WWII) | ~200–400 kg | 30–50+ m | Dominant anomaly |
See simulated detections on a live map at real-world affected locations.
▶ Launch Atlas Demo