Preliminary Site Screening for Single-Family Tension-Leg Seastead Prototypes near Anguilla

This is a high-level screening summary based on geography, maritime zones, bathymetry constraints, and general Caribbean/open-Atlantic wave climate logic. It is not a hydrographic, legal, engineering, or permitting determination. Before any deployment, you would need:

Bottom-line answer: based on your stated requirements, there are effectively no realistic locations in international waters within 2000 miles of Anguilla that are both:
  1. more than 200 nautical miles from every country,
  2. shallower than 100 ft (~30.5 m), and
  3. likely to have sandy bottom suitable for mooring screws.
In the Atlantic/Caribbean region, areas that qualify as true high seas are generally deep ocean, not shallow banks.

1) Executive Summary

Question Finding
Hidden prototype sites in Anguilla territorial waters / EEZ with sandy bottom and <100 ft depth? Possibly yes, especially in selected leeward areas around outer islands/banks, but requires local chart review and benthic survey.
“Over-the-horizon” sites from Anguilla’s main inhabited areas? Yes, potentially, especially on the far side of outlying islands/banks or at sufficient distance offshore. Exact visibility depends on observer height and structure elevation.
International waters within 2000 miles of Anguilla, <100 ft deep, sandy bottom? No credible candidates identified. Shallow sandy banks in the region are almost always within some state’s territorial sea, EEZ, or extended shelf jurisdiction—not high seas.
Wave conditions Sheltered near-island bank sites can be moderate in normal trade-wind conditions, but hurricane and long-period swell exposure remain major design drivers.

2) Key Constraint: Why International-Waters Candidates Likely Do Not Exist

Your requirement set is unusually restrictive:

In that radius, shallow seabed is overwhelmingly associated with:

But areas beyond all countries’ 200 nm EEZs in the Atlantic are mostly abyssal plain and deep ocean basins, typically thousands of meters deep. So the combination high seas + <100 ft depth + sandy bottom is not realistic here.

3) International Waters Candidates Matching All Requirements

Candidate Center Lat/Lon Direction / Distance from Nearest Country Approx. Area 500 ft Grid Capacity Wave Climate Status
None credibly identified N/A N/A 0 0 Open Atlantic high-seas areas are generally much rougher than sheltered island-bank sites and are deep ocean, not <100 ft banks Does not meet bathymetry requirement
Therefore: if shallow screw-anchor deployment and 100 ft installation depth are firm constraints, your practical search area is inside Anguilla territorial waters / EEZ, not in true international waters.

4) Practical Search Areas Near Anguilla That May Fit the Spirit of Your Requirements

The locations below are screening concepts, not confirmed deployable sites. I am listing them because they may satisfy the practical goals of:

Important: exact depth, seabed type, habitat, and navigation restrictions must be confirmed locally. Some areas around Anguilla’s satellite islands and cays include reefs, hardbottom, coral habitat, steep drop-offs, marine protected values, and exposed wave climates.

4.1 Conceptual Candidate Areas in Anguilla Waters

Concept Area Approx. Center Lat/Lon Likely Visibility from Main Anguilla Depth / Bottom Likelihood Approx. Screening Area Potential Approx. 500 ft Grid Capacity General Wave Notes Comments
Leeward side of Scrub Island platform / adjacent bank pockets 18.29, -62.95 Potentially partially screened by island geometry depending on exact spot and structure height Some shallow bank areas may exist; mixed sand and hardbottom likely Highly site-specific; perhaps 0.2-1.0 sq mi of potentially screenable sub-areas, not continuous proven sand ~11 to 55 units per sq mi on a pure geometric basis Can be calmer on leeward side in normal trades, but hurricane exposure remains severe Probably one of the more realistic prototype-search zones
Far side of Dog Island / nearby bank margins 18.27, -63.25 Potentially less visible from populated coastlines if placed on screened side Possible shallow sandy patches, but reef/hardbottom likely in many places Maybe 0.1-0.6 sq mi of candidate patches after exclusions ~5 to 33 units per sq mi equivalent More exposed than heavily sheltered sites; trade-wind and northerly swell screening depends on aspect Would need strong ecological and chart screening
Outer shelf / bank pockets east or northeast of Anguilla, behind local relief or below practical visibility limits 18.32, -62.86 Some sites may be over practical horizon for shoreline observers Possible sand sheets on bank top if shallow enough; local bathymetry uncertain without survey Unknown; could be several disconnected small polygons rather than one area Depends entirely on mapped sand polygons Generally more exposed to Atlantic swell than west/southwest lee areas May better satisfy “out of sight” but worse metocean
Selected concealed pockets within Anguilla Bank but away from common tourism sightlines 18.24, -63.05 Can be low-visibility if distant enough and low-profile Best chance of finding sand in shallow water, but traffic/use/conflict risk rises Potentially multiple small sites Depends on exclusions, setbacks, and navigation lanes Typically more manageable in normal weather if well chosen Most practical from logistics and installation standpoint

5) How Many Seasteads per Area on a 500 ft Grid?

A 500 ft square grid implies each unit occupies:

500 ft × 500 ft = 250,000 sq ft

One square mile is:

27,878,400 sq ft

So the maximum geometric density is:

27,878,400 / 250,000 ≈ 111.5 units per square mile

In practice, usable density will be much lower after accounting for:

A more realistic planning factor for prototype deployment may be something like 25% to 60% of pure grid maximum, depending on mooring geometry. That yields:

Usable Area Pure Geometric Max Practical Planning Range
0.1 sq mi 11 units 3-7 units
0.2 sq mi 22 units 6-13 units
0.5 sq mi 55 units 14-33 units
1.0 sq mi 111 units 28-67 units

6) Wave Height Considerations

Because you mentioned a small tension-leg system, the key issue is not only average wave height but:

General Caribbean / Atlantic Context Near Anguilla

Exposure Class Typical Condition Description General Significant Wave Height Notes
Sheltered/leeward bank site Protected from prevailing easterly trade seas by island or bank geometry Often relatively moderate in normal conditions, but still can see swell events and storm amplification
Partially exposed bank margin Some protection, but open to one or more swell windows More variable; northerly winter swell and Atlantic events matter
Atlantic-exposed outer side Open fetch to Atlantic Higher routine sea states, stronger swell energy, much tougher design environment
Hurricane conditions Extreme event case Potentially catastrophic loads; governs ultimate survival design regardless of normal-wave comfort

If your objective is a stable and livable first prototype, you likely want:

7) “Over the Horizon” from Anguilla

Yes, “over the horizon” can be feasible depending on observer eye height and seastead elevation. As a rough rule, sea-level horizon distance for a shoreline observer is limited. A low-profile floating structure can become hard to see at moderate distances, especially if:

However, a taller superstructure, mast, or lighting can remain visible from farther away. So “not visible from shore” should be verified by:

8) Recommended Next-Step Workflow

  1. Abandon the international-waters shallow-bank search unless your 100 ft depth requirement changes dramatically.
  2. Focus on Anguilla-controlled waters, especially screened or leeward outer-bank pockets.
  3. Obtain:
  4. Create a screening matrix using:
  5. Do a desktop viewshed analysis from key public shorelines in Anguilla.
  6. Shortlist 3-5 sites and conduct on-water reconnaissance.

9) Direct Answer to Your Questions

Your Question Answer
Are there locations in international waters within 2000 miles of Anguilla that are less than 100 ft deep and have sandy bottoms? No realistic candidates identified.
What locations fit the requirements? None in true international waters under the stated depth and bottom constraints. Practical candidates are instead within Anguilla waters, such as screened/leeward pockets near Scrub Island, Dog Island, and selected Anguilla Bank areas.
Give lat/lon for center of area and direction-distance from nearest country For true international-waters qualifying sites: none. For practical Anguilla-area screening concepts, approximate centers are listed above.
How big are these locations? True international-waters qualifying areas: 0. Practical Anguilla-area candidate patches may range from very small polygons up to perhaps fractions of a square mile, subject to survey.
How many seasteads on a 500 ft grid? For true international-waters qualifying areas: 0. For shallow candidate patches in Anguilla waters, use about 111 units per sq mi maximum geometric density, with materially lower practical density.
How are wave heights? Near-Anguilla leeward bank sites can be moderate in normal conditions, but tropical cyclones remain the dominant design hazard. Open high-seas Atlantic locations would generally be rougher and much deeper.

10) Conclusion

If your installation depth limit is 100 feet and you need sandy bottom for screw anchors, then your first prototype program should almost certainly be pursued in Anguilla territorial waters or EEZ, not in international waters. The best opportunities are likely:

If you want, I can next generate one of these in HTML as well: