This page collects answers to your design, fisheries, and operational questions about using a 1:4 scale seastead USV as a solar-powered, relocating “eFAD” near Anguilla.
1. Prior Art: Have Other People Made Relocatable FADs?
Yes, but they are still uncommon. Most “smart FAD” work has focused on reporting (GPS, echosounders, AIS) rather than active propulsion. Research institutions and regional fisheries bodies (e.g., SPC/Pacific Community, NOAA, and some Caribbean projects) have trialed drifting and relocatable FADs. The term eFAD is increasingly used for buoys that transmit biomass or location data.
2. Towing Force at 0.25 MPH
At 0.25 MPH (≈ 0.11 m/s) drag is dominated by the wetted ropes, nets, and buoyancy lines. A typical artisanal FAD with 100–150 ft of line, a buoy, and some netting has a lot of “wetted string” area.
- Typical artisanal FAD: roughly 15–40 lbf of drag. Ropes have a high drag coefficient (~1.0–1.2) and there are many line-meters in the water.
- Hydrodynamically optimized FAD (streamlined float, lines bundled or retracted, minimal netting): roughly 5–15 lbf.
Because drag scales roughly with v² for the bluff bodies and with skin-friction for long ropes, staying under 0.5 mph keeps forces very low and easily within the ability of a few small thrusters.
3. Will the 1:4 Scale Seastead Alone Act as a FAD?
Probably yes, but weaker than a purpose-built FAD. Fish aggregate under floating objects for shade, shelter, and the food-chain micro-habitat that grows on submerged structure.
- Your model will have three vertical legs, cross-bracing, three airplane-style stabilizers, and solar overheads producing shade.
- That complexity is attractive to small pelagics, jacks, and rainbow runners.
- To improve it, hanging a few weighted streamers or a short “curtain” of rope/net underneath increases the visual and sonar signature dramatically.
4. Are Six Blue Robotics Thrusters Enough?
Assuming the T200 (or comparable M200 motor series) thrusters, each can produce roughly 5 lbf of bollard thrust. Six gives you ~30 lbf maximum. Towing a drag-optimized FAD at 0.25 MPH might require only 2–6 lbf.
You therefore have massive overhead: you can push through wind, hold station against an adverse eddy, or surge to 3–4 kts when repositioning. At 0.25 MPH the electrical draw will be minimal—likely well under 50 W for the whole array—leaving most solar budget for Starlink, cameras, sonar, and lights.
5. Timing: How Soon Do Fish Arrive?
- First 24–48 hours: small baitfish, juvenile jacks, and curious pelagics often investigate a new object.
- 2–7 days: a mini food-web establishes; larger gamefish become resident if the location has passing traffic.
- Moving slowly (0.25 MPH): this is essentially “drift speed.” Most FAD-associated species (mahi, tuna, wahoo, billfish) can follow or remain attached to a slow-moving object, especially if motion is smooth and vibration is low. Rapid direction changes are more disruptive than slow linear movement.
6. Will Fish Follow into Shallow Water?
Large pelagics (tuna, wahoo, billfish) generally avoid the flat, shallow bank. They will, however, follow a FAD right to the shelf edge / drop-off. Anguilla’s northeast drop-off (roughly 5–6 miles offshore near Island Harbor) is therefore the ideal “destination.”
If you bring the FAD to that lip and hold position, local handliners and trolling boats can access prime fish without burning fuel for 40-mile searches. Do not expect the same schools to follow you into 30 ft of water; they will peel off as depth shoals rapidly.
7. Legal Protections in Anguilla
Anguilla’s waters are managed under the Fisheries Protection Act (and related marine parks regulations). In most Caribbean open-access fisheries, deploying a FAD does not grant you exclusive fishing rights over the surrounding water. Other licensed fishers can legally fish nearby.
- Permits: you will almost certainly need a FAD deployment permit from the Department of Fisheries and Marine Resources. AIS requirements are common.
- Exclusivity workaround: because your FAD is “smart,” your practical defense is speed and data, not a legal fence. You can know where the fish are, move the asset if outsiders converge, and sell the service (location intel + date with the FAD) rather than claiming the fish themselves.
- Data sales: if you hold the Starlink/sonar feed, you own the information, which can be monetized with local fishers or charter boats without asserting ownership of the water.
8. Rules of Thumb for Artisanal FADs
| Spacing | Typically 3–5 nautical miles apart to reduce competition and overlap, though in some island chains 1–2 nm is tolerated if currents differ. |
|---|---|
| Total in-water mass (buoy + rope/net, no anchor chain) | ~40–120 kg (≈ 90–260 lbs). Your 100 lb estimate is realistic. |
| Biomass around a healthy artisanal FAD | Highly variable; 100–1,000+ lbs depending on depth, season, and FAD maturity. |
| Catch per visit (small open boat) | ~40–120 lbs; 80 lbs is a solid average for a good day. |
| Revisit frequency | Every 2–4 days in good weather if the FAD is inside 15 nm; weekly if farther out or weather is rough. |
9. Can You “Hear” the Fish?
Yes, to a degree. A simple echosounder (fishfinder) is the standard tool for estimating biomass under a FAD. For a smart system, a low-power multi-frequency echosounder module can profile the water column and transmit summaries over Starlink.
Passive acoustics: some species (snappers, groupers, certain pelagics) grunt and pop. Hydrophones + edge AI can classify sounds and estimate relative abundance. It is harder than using sonar but feasible as a secondary/backup sensor.
10. Overall Assessment of the Idea
This is one of the more credible “stepping stone” seastead concepts because it has a revenue model on day one. Instead of asking “how do we pay for floating real estate?” you are asking “how do we make a better FAD?” The seastead form factor solves station-keeping, solar power, and payload—while the FAD application pays for sea-trials.
Smart FAD Economics Calculator Weekly P&L
Excludes labor, insurance, Starlink/data fees, maintenance, port fees, and weather downtime.