Western Europe · Isolated Landmass
Île d’Yeu
France
Île d’Yeu is strongest on Population Capacity 8/10 — Nearly 4,900 permanent residents and more than 2,300 households provide extensive shelter, sanitation and service headroom compared with twenty survivors.. Its clearest scored constraint is Defensibility 1/10 — The whole island has a long public coastline, harbour, roads and distributed housing rather than a defended perimeter. Twenty survivors cannot hold the canonical island continuously; a fort is not substituted..
Overall
4.7 out of 10Defensibility
1 out of 10Isolation
6 out of 10Sustainability
7 out of 10Ranking context
How this base ranks
Global
#58 of 91 · Top 63.74%
Region · Western Europe
#7 of 9 · Top 77.78%
Base Type · Isolated Landmass
#10 of 19 · Top 52.63%
Field assessment
At a glance
Bottom Line
For the fixed 20-person Base boundary, the most important endurance constraint is Maintenance Resilience 4/10 — Fishing, ordinary buildings, local farming and stored water remain useful after utility degradation, but potable water and electricity depend on submarine mainland connections and maintained distribution systems. 2026 water stress demonstrates limited margin..
Biggest Trade-off
The central trade-off is the catalogue's strongest evidenced dimension, Population Capacity at 8/10, against its weakest evidenced dimension, Defensibility at 1/10.
Most Likely Failure
The clearest evidenced failure pressure is Maintenance Resilience: Fishing, ordinary buildings, local farming and stored water remain useful after utility degradation, but potable water and electricity depend on submarine mainland connections and maintained distribution systems. 2026 water stress demonstrates limited margin.
Score rationale
Why it scores this way
Defensibility · 1/10
The whole island has a long public coastline, harbour, roads and distributed housing rather than a defended perimeter. Twenty survivors cannot hold the canonical island continuously; a fort is not substituted.
Advantages
- Positive credit is limited to what supports the Defensibility score of 1/10; the component rationale is: The whole island has a long public coastline, harbour, roads and distributed housing rather than a defended perimeter. Twenty survivors cannot hold the canonical island continuously; a fort is not substituted.
Limitations
- Do not infer additional Defensibility capability outside the fixed Base boundary or beyond the recorded evidence.
Isolation · 6/10
Twenty-plus kilometres of open sea and only about 4,900 permanent residents provide materially advantageous separation, but year-round ferry access and a nearby populated mainland keep the island below stronger remote-ocean classes.
Advantages
- Positive credit is limited to what supports the Isolation score of 6/10; the component rationale is: Twenty-plus kilometres of open sea and only about 4,900 permanent residents provide materially advantageous separation, but year-round ferry access and a nearby populated mainland keep the island below stronger remote-ocean classes.
Limitations
- Do not infer additional Isolation capability outside the fixed Base boundary or beyond the recorded evidence.
Sustainability · 7/10
A functioning year-round community with thousands of homes, sanitation, 7,000 cubic metres of potable-water storage, electricity, fishing, agriculture and food retail gives strong habitat for twenty. Main utility supply arrives from the mainland and prevents a stronger class.
Advantages
- Positive credit is limited to what supports the Sustainability score of 7/10; the component rationale is: A functioning year-round community with thousands of homes, sanitation, 7,000 cubic metres of potable-water storage, electricity, fishing, agriculture and food retail gives strong habitat for twenty. Main utility supply arrives from the mainland and prevents a stronger class.
Limitations
- Do not infer additional Sustainability capability outside the fixed Base boundary or beyond the recorded evidence.
Survival horizons
How survival changes over time
First 7 days: current defence/contact profile
First 7 Days
This horizon does not invent future upgrades or resupply. It carries the current evaluated conditions forward and keeps unknown future capability uncredited.
Positive factors
- The stronger current condition in this horizon is Exposure Control 6/10 — Sea separation strongly restricts external walkers and concentrates normal arrivals around harbour/ferry systems, while the small island's own population and accessible coastline create many local movement routes. The result is advantageous but not tightly controlled..
Risks
- The weaker current condition in this horizon is Defensibility 1/10 — The whole island has a long public coastline, harbour, roads and distributed housing rather than a defended perimeter. Twenty survivors cannot hold the canonical island continuously; a fort is not substituted.; no better future state is assumed.
First 100 days: current habitat/capacity profile
First 100 Days
This horizon does not invent future upgrades or resupply. It carries the current evaluated conditions forward and keeps unknown future capability uncredited.
Positive factors
- The stronger current condition in this horizon is Population Capacity 8/10 — Nearly 4,900 permanent residents and more than 2,300 households provide extensive shelter, sanitation and service headroom compared with twenty survivors..
Risks
- The weaker current condition in this horizon is Sustainability 7/10 — A functioning year-round community with thousands of homes, sanitation, 7,000 cubic metres of potable-water storage, electricity, fishing, agriculture and food retail gives strong habitat for twenty. Main utility supply arrives from the mainland and prevents a stronger class.; no better future state is assumed.
Long term: current resource/maintenance profile
Long Term
This horizon does not invent future upgrades or resupply. It carries the current evaluated conditions forward and keeps unknown future capability uncredited.
Positive factors
- The stronger current condition in this horizon is Maintenance Resilience 4/10 — Fishing, ordinary buildings, local farming and stored water remain useful after utility degradation, but potable water and electricity depend on submarine mainland connections and maintained distribution systems. 2026 water stress demonstrates limited margin..
Risks
- The weaker current condition in this horizon is Maintenance Resilience 4/10 — Fishing, ordinary buildings, local farming and stored water remain useful after utility degradation, but potable water and electricity depend on submarine mainland connections and maintained distribution systems. 2026 water stress demonstrates limited margin.; no better future state is assumed.
Tactical assessment
Practical Reality
Reality Check
Scores apply only to the defined Base and exactly 20 capable adults. Unknown, excluded or external assets are not credited as hidden capability.
Best Use
Within the evaluated boundary, treat Population Capacity as the primary operational strength; do not promote that score into capabilities the evidence does not establish.
Key Risk
Maintenance Resilience is the key evidenced long-duration risk: Fishing, ordinary buildings, local farming and stored water remain useful after utility degradation, but potable water and electricity depend on submarine mainland connections and maintained distribution systems. 2026 water stress demonstrates limited margin.
Strengths
- One of the strongest scored dimensions is Population Capacity 8/10 — Nearly 4,900 permanent residents and more than 2,300 households provide extensive shelter, sanitation and service headroom compared with twenty survivors..
- One of the strongest scored dimensions is Sustainability 7/10 — A functioning year-round community with thousands of homes, sanitation, 7,000 cubic metres of potable-water storage, electricity, fishing, agriculture and food retail gives strong habitat for twenty. Main utility supply arrives from the mainland and prevents a stronger class..
- One of the strongest scored dimensions is Isolation 6/10 — Twenty-plus kilometres of open sea and only about 4,900 permanent residents provide materially advantageous separation, but year-round ferry access and a nearby populated mainland keep the island below stronger remote-ocean classes..
Weaknesses
- One of the weakest scored dimensions is Defensibility 1/10 — The whole island has a long public coastline, harbour, roads and distributed housing rather than a defended perimeter. Twenty survivors cannot hold the canonical island continuously; a fort is not substituted..
- One of the weakest scored dimensions is Maintenance Resilience 4/10 — Fishing, ordinary buildings, local farming and stored water remain useful after utility degradation, but potable water and electricity depend on submarine mainland connections and maintained distribution systems. 2026 water stress demonstrates limited margin..
- One of the weakest scored dimensions is Resource Security 4/10 — The island begins with major potable-water storage plus active fisheries, local agriculture and food retail, but fresh water is piped from the mainland and electricity arrives through submarine cables. Local food pathways are meaningful but not broad self-sufficiency, leaving an important utility fragility..
Assumptions / constraints
- Only assets inside the recorded Core Base and immediate operating boundary are credited; excluded surroundings and unproven future access remain outside the score.
Decision context
Rivals / Alternatives
Similar rival
Seychelles
Seychelles · Isolated Landmass
Seychelles keeps the same isolated landmass strategy, with only 0.0 points between the overall scores and closely matched defensibility pressure.
Overall 4.7/10
Strongest alternative
Heligoland
Germany · Isolated Landmass
Heligoland scores 6.3 overall versus 4.7, adding a stronger isolation profile while staying relevant as another isolated landmass.
Overall 6.3/10
Wildcard rival
San Felipe Fortress
Colombia · Fortified Structure
San Felipe Fortress changes the strategy: it is a fortified structure with a defensibility edge, while Île d’Yeu holds more of the isolation advantage.
Overall 3.7/10