Seastead Site Analysis — Anguilla Region

1 Scope & Constraints

Parameter	Requirement
Platform type	Single-family tension-leg seastead (mini oil-platform concept)
Mooring	Helical mooring screws → sandy bottom required
Max installation depth	100 ft (≈ 30 m)
Visual concealment	Not visible from Anguilla main-island residents (hidden behind Scrub, Dog, or over the horizon)
Jurisdiction preference	Anguilla territorial sea or EEZ first; international waters as stretch goal
Grid spacing (if clustered)	500 ft (≈ 152 m) center-to-center

2 International Waters — Why No Shallow Sandy Sites Exist

❌ No International-Water Shallow Sandy Sites Within 2 000 mi of Anguilla

The Caribbean is an enclosed basin. Every bank shallow enough for your criteria falls well inside at least one nation's 200 nm Exclusive Economic Zone:

Bank / Feature	Nearest Nation	Distance to Nation	Why It Fails
Bahama Banks	Bahamas	0–50 nm	Entirely within Bahamian EEZ
Navidad Bank	Dominican Republic	~40 nm	Within Dominican EEZ; shallow but claimed
Mouchoir Bank	Turks & Caicos	~20 nm	British EEZ (Turks & Caicos)
Silver Bank	Dominican Republic	~60 nm	Within Dominican EEZ
Pedro Bank	Jamaica	~40 nm	Jamaican EEZ
Serranilla Bank	Colombia / Honduras	~80 nm	Disputed / Colombian claim
Deep Atlantic (beyond 200 nm)	—	> 200 nm	Depths 8 000–20 000+ ft — far too deep

The fundamental problem: Within 2 000 miles, all shallow (≤100 ft) sandy-bottom areas are banks on continental shelves or island arcs — and every one is claimed by a coastal state. Truly international waters in the Atlantic begin where the seafloor plunges to abyssal depths (13 000+ ft). Tension-leg platforms can theoretically operate in deep water (that's what deep-sea oil rigs do), but your current 100 ft installation limit and screw-mooring requirement make this impractical.

💡 If you later extend to deep-water installation:

Open-ocean locations in the central Atlantic (Sargasso Sea region) could be genuinely in international waters — but they require free-standing tension-leg designs anchored to the seabed at 10 000+ ft, a completely different engineering challenge.

3 Candidate Locations — Anguilla EEZ

All sites below are on the Anguilla Bank, a broad, gently-sloping carbonate shelf with predominantly sandy/coral-sand bottom. The 100-ft (30 m) contour generally lies 5–20 nm offshore, depending on direction.

Location A — Dog Island NW Shelter Zone ★ Top Pick

Center coordinates	18.33°N, 63.14°W
Direction & distance from Dog Island	~3 nm WNW of Dog Island
Distance from Anguilla main island	~17 nm NW
Visibility from main island	✅ Hidden behind Dog Island (Dog Is. ridgeline ~30 m elevation blocks line of sight)
Approx. water depth	18–30 ft (5–9 m)
Bottom type	Medium-fine carbonate sand, occasional coral patches
Shelter quality	Excellent — Dog Island blocks NE & E fetch for 2+ nm; dominant trade-wind waves heavily attenuated

Usable Area & Capacity

Metric	Estimate
Area with depth 10–30 m (screw-mooring sweet spot)	~8 nm²
Gross capacity at 500 ft (152 m) grid	~56,000 slots
Practical capacity (~12 % utilization — lanes, buffer, coral avoidance)	~6,700 seasteads

Wave Climate

Condition	Sig. Wave Height	Notes
Calm trades	0.3–0.6 m (1–2 ft)	Very sheltered by Dog Island
Typical trades	0.5–1.0 m (1.6–3.3 ft)	Fetch limited to ~2 nm from shelter
Strong trades / N swell	0.8–1.5 m (2.6–4.9 ft)	Some wrap around Dog Island W tip
Winter long-period swell	1.0–1.8 m (3.3–5.9 ft)	NE swell; shelter still effective
Hurricane (Cat 3+)	5–10+ m (16–33+ ft)	Full shelter breakdown — require disconnect/relocation protocol

Typical conditions:

0.5–1.0 m

Location B — Dog Island West Platform Good

Center coordinates	18.28°N, 63.18°W
Direction & distance from Dog Island	~5 nm WSW of Dog Island
Distance from Anguilla main island	~15 nm W
Visibility from main island	✅ Over the horizon (~8 nm horizon from sea level + Dog Island intervening)
Approx. water depth	20–35 ft (6–11 m)
Bottom type	Sandy with seagrass patches; verify site-specific for coral
Shelter quality	Moderate — good from NE due to Dog Island; somewhat open to N and NW

Usable Area & Capacity

Area with depth 10–30 m	~20 nm²
Practical capacity (~12 %)	~16,800 seasteads

Wave Climate

Condition	Sig. Wave Height
Calm trades	0.5–0.8 m
Typical trades	0.8–1.3 m
Strong / N swell	1.2–2.0 m
Hurricane	5–10+ m

Typical conditions:

0.8–1.3 m

Location C — Anguilla Bank Northwest Deep Large Area

Center coordinates	18.38°N, 63.25°W
Direction & distance from Dog Island	~10 nm NW of Dog Island
Distance from Anguilla main island	~23 nm NW
Visibility from main island	✅ Over the horizon (well beyond ~8 nm visible horizon)
Approx. water depth	25–50 ft (8–15 m)
Bottom type	Sandy; more open — likely fewer coral heads
Shelter quality	Limited — open to NE trades; acceptable for tension-leg but higher fatigue loads

Usable Area & Capacity

Area with depth 10–30 m	~50 nm²
Practical capacity (~10 % — more conservative due to exposure)	~35,000 seasteads

Wave Climate

Condition	Sig. Wave Height
Calm trades	0.5–1.0 m
Typical trades	1.0–1.5 m
Strong / N swell	1.5–2.5 m
Hurricane	6–12+ m

Typical conditions:

1.0–1.5 m

Location D — Scrub Island East / ESE Exposed

Center coordinates	18.26°N, 62.92°W
Direction & distance from Scrub Island	~3 nm ESE of Scrub Island
Distance from Anguilla main island	~10 nm ESE
Visibility from main island	✅ Hidden behind Scrub Island's ridgeline (~20 m elevation)
Approx. water depth	15–30 ft (5–9 m)
Bottom type	Sandy with some coral heads — survey required
Shelter quality	Poor — directly open to prevailing ENE trades and Atlantic swell

Usable Area & Capacity

Area with depth 10–30 m	~5 nm²
Practical capacity (~8 % — higher exposure, coral avoidance)	~2,800 seasteads

Wave Climate

Condition	Sig. Wave Height
Calm trades	0.8–1.2 m
Typical trades	1.2–1.8 m
Strong / NE swell	1.8–2.8 m
Hurricane	6–12+ m

Typical conditions:

1.2–1.8 m

⚠ Caveat: Tension-leg platforms are designed for open-ocean conditions, so these waves are manageable — but fatigue life will be shorter and comfort lower than sheltered sites. Recommended for prototype testing, not long-term residential deployment.

Location E — South Anguilla / Sandy Island South Good

Center coordinates	18.16°N, 63.12°W
Direction & distance from Sandy Island	~3 nm S of Sandy Island
Distance from Anguilla main island	~7 nm SSW
Visibility from main island	✅ Over the horizon from most south-coast viewpoints (~4–5 nm horizon from low shore)
Approx. water depth	20–40 ft (6–12 m)
Bottom type	Sand with seagrass; verify for coral patches
Shelter quality	Moderate — Anguilla main island provides partial wind shadow from NE trades

Usable Area & Capacity

Area with depth 10–30 m	~15 nm²
Practical capacity (~12 %)	~12,600 seasteads

Wave Climate

Condition	Sig. Wave Height
Calm trades	0.4–0.8 m
Typical trades	0.8–1.3 m
Strong / swell	1.2–2.0 m
Hurricane	5–10+ m

Typical conditions:

0.8–1.3 m

4 Summary Comparison

Site	Coords	Depth	Hidden?	Typ. Waves	Usable Area	Practical Capacity	Rating
A — Dog NW	18.33°N 63.14°W	18–30 ft	✅	0.5–1.0 m	8 nm²	~6,700	★ Best
B — Dog W	18.28°N 63.18°W	20–35 ft	✅	0.8–1.3 m	20 nm²	~16,800	Good
C — Bank NW	18.38°N 63.25°W	25–50 ft	✅	1.0–1.5 m	50 nm²	~35,000	Large
D — Scrub E	18.26°N 62.92°W	15–30 ft	✅	1.2–1.8 m	5 nm²	~2,800	Exposed
E — South Bank	18.16°N 63.12°W	20–40 ft	✅	0.8–1.3 m	15 nm²	~12,600	Good

5 How Capacity Was Calculated

For each site, capacity was estimated as follows:

500 ft grid spacing = 152.4 m center-to-center
Gross density = 1 seastead per (152.4 m)² = 1 per 23,227 m²
1 nm² = 3,429,905 m² → ~147.6 slots per nm² (gross)
Utilization factor applied (8–12%) accounts for: navigation channels, ecological buffer zones, coral avoidance, infrastructure corridors, and safety margins
"Usable area" is the estimated area within the depth window and on sandy bottom (excluding known coral reef zones)

These are preliminary estimates. A proper hydrographic survey with side-scan sonar will refine the sandy-vs-reef areas significantly.

6 Regulatory & Next Steps

⚠ Before Proceeding — You Will Need:

Anguilla Government approval — The Anguilla Physical Planning Department and Executive Council will need to authorize marine development within the territory's waters.
Environmental Impact Assessment — Required for any development affecting coral reefs, seagrass beds, or marine habitats.
Hydrographic survey — Side-scan sonar + grab samples to confirm sandy bottom vs. coral at each specific site.
Marine spatial planning consultation — Coordination with fisheries, navigation authorities, and neighboring territories.
Hurricane preparedness plan — Tension-leg disconnect protocol or proven survivability in Cat 5 conditions (sustained 157+ mph winds, 10+ m seas).

7 Wave Climate Notes

Dominant Conditions

Trade winds blow from ENE to NE at 10–20 kts for most of the year, generating locally-wind-seas of 0.5–1.5 m.
Atlantic swell from North Atlantic storms (Oct–Mar) produces long-period (8–14 sec) swells from the NE that can reach 1.5–2.5 m in open water but are attenuated by the shallow Anguilla Bank and blocked by islands.
Summer (Jun–Sep) is generally calmer with more easterly winds and lower seas, but hurricane risk peaks.

Hurricane Considerations

The Caribbean hurricane season runs June 1 – November 30. Anguilla is in the high-risk zone. Your tension-leg design must either:

Survive in place: Design for Cat 5 conditions (sustained winds >157 mph, significant wave height >10 m, storm surge +3–5 m). This is the approach used by offshore oil platforms.
Disconnect and relocate: Detach from mooring screws and move to a safe harbor or deep water. This requires quick-release tension leg connections and towing capability.

A hybrid approach — surviving Cat 1–3 in place, disconnecting for Cat 4–5 — is likely the most practical.

8 Recommendation

🎯 Start with Location A (Dog Island NW)

This site offers the best combination of:

✅ Shallow sandy bottom (18–30 ft) — well within your 100 ft limit
✅ Excellent shelter from Dog Island — lowest wave loads of all sites
✅ Completely hidden from Anguilla main island residents
✅ Sufficient area for initial prototypes (~6,700 seastead capacity)
✅ Within Anguilla's EEZ and territorial waters

Phase 1: Deploy 1–3 prototypes at Location A for 12-month sea trial.
Phase 2: Expand to Location B or E for larger community.
Phase 3: If deep-water installation capability is developed, explore open-ocean international sites.

⚓ Seastead Site Analysis

1 Scope & Constraints

2 International Waters — Why No Shallow Sandy Sites Exist

❌ No International-Water Shallow Sandy Sites Within 2 000 mi of Anguilla

💡 If you later extend to deep-water installation:

3 Candidate Locations — Anguilla EEZ

Usable Area & Capacity

Wave Climate

Usable Area & Capacity

Wave Climate

Usable Area & Capacity

Wave Climate

Usable Area & Capacity

Wave Climate

Usable Area & Capacity

Wave Climate

4 Summary Comparison

5 How Capacity Was Calculated

6 Regulatory & Next Steps

⚠ Before Proceeding — You Will Need:

7 Wave Climate Notes

Dominant Conditions

Hurricane Considerations

8 Recommendation

🎯 Start with Location A (Dog Island NW)