Africa · Isolated Landmass
Zanzibar Island
Tanzania
Zanzibar Island is strongest on Population Capacity 10/10 — Unguja already supports more than 1.3 million residents with large-scale housing and public/commercial infrastructure, placing it in the highest credible capacity class relative to twenty survivors.. Its clearest scored constraint is Defensibility 1/10 — Unguja is a large, densely inhabited island with extensive coastline, towns, roads and ports. Twenty survivors cannot defend the canonical island as one perimeter, and no resort, Stone Town district or rural compound is substituted..
Overall
3.3 out of 10Defensibility
1 out of 10Isolation
1 out of 10Sustainability
8 out of 10Ranking context
How this base ranks
Global
#86 of 91 · Top 94.51%
Region · Africa
#8 of 11 · Top 72.73%
Base Type · Isolated Landmass
#19 of 19 · Top 100%
Field assessment
At a glance
Bottom Line
For the fixed 20-person Base boundary, the most important endurance constraint is Maintenance Resilience 3/10 — Ordinary housing, agriculture/fisheries and groundwater retain some passive/local value, but the water system depends on extensive borehole abstraction/distribution and faces salinisation/protection/monitoring problems. Electricity is imported by submarine cable and the current policy explicitly states there is no functional backup generation, so technical failure cascades are substantial..
Biggest Trade-off
The central trade-off is the catalogue's strongest evidenced dimension, Population Capacity at 10/10, against its weakest evidenced dimension, Defensibility at 1/10.
Most Likely Failure
The evaluation leaves this material failure condition unresolved: Unguja's electricity is imported by submarine cable with no functional backup generation, while large-scale groundwater supply/distribution is infrastructure-dependent. The scores remain numeric, but this coupled utility vulnerability requires package adjudication rather than being hidden inside a generic low resource score.
Score rationale
Why it scores this way
Defensibility · 1/10
Unguja is a large, densely inhabited island with extensive coastline, towns, roads and ports. Twenty survivors cannot defend the canonical island as one perimeter, and no resort, Stone Town district or rural compound is substituted.
Advantages
- Positive credit is limited to what supports the Defensibility score of 1/10; the component rationale is: Unguja is a large, densely inhabited island with extensive coastline, towns, roads and ports. Twenty survivors cannot defend the canonical island as one perimeter, and no resort, Stone Town district or rural compound is substituted.
Limitations
- Do not infer additional Defensibility capability outside the fixed Base boundary or beyond the recorded evidence.
Isolation · 1/10
Sea separation from mainland Tanzania slows external walkers, but more than 1.3 million residents already live inside Unguja and the island has normal regional ferry/air connectivity. The dominant zombie-pressure source is therefore internal, making effective isolation very low.
Advantages
- Positive credit is limited to what supports the Isolation score of 1/10; the component rationale is: Sea separation from mainland Tanzania slows external walkers, but more than 1.3 million residents already live inside Unguja and the island has normal regional ferry/air connectivity. The dominant zombie-pressure source is therefore internal, making effective isolation very low.
Limitations
- Do not infer additional Isolation capability outside the fixed Base boundary or beyond the recorded evidence.
Sustainability · 8/10
A mature island society supporting more than 1.3 million people has extensive housing, markets, healthcare, sanitation, groundwater supply, agriculture/fisheries and electricity distribution, giving twenty people a very strong current habitat. Water-source pressure and mainland-dependent electricity prevent a 9-class rating.
Advantages
- Positive credit is limited to what supports the Sustainability score of 8/10; the component rationale is: A mature island society supporting more than 1.3 million people has extensive housing, markets, healthcare, sanitation, groundwater supply, agriculture/fisheries and electricity distribution, giving twenty people a very strong current habitat. Water-source pressure and mainland-dependent electricity prevent a 9-class rating.
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 2/10 — The sea blocks direct mainland foot movement, but Unguja contains a very large resident population, multiple urban/rural centres, ports and a broad road network. Twenty survivors cannot monitor or funnel the island's internal movement effectively..
Risks
- The weaker current condition in this horizon is Defensibility 1/10 — Unguja is a large, densely inhabited island with extensive coastline, towns, roads and ports. Twenty survivors cannot defend the canonical island as one perimeter, and no resort, Stone Town district or rural compound is 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 10/10 — Unguja already supports more than 1.3 million residents with large-scale housing and public/commercial infrastructure, placing it in the highest credible capacity class relative to twenty survivors..
Risks
- The weaker current condition in this horizon is Sustainability 8/10 — A mature island society supporting more than 1.3 million people has extensive housing, markets, healthcare, sanitation, groundwater supply, agriculture/fisheries and electricity distribution, giving twenty people a very strong current habitat. Water-source pressure and mainland-dependent electricity prevent a 9-class rating.; 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 Resource Security 4/10 — Unguja has extensive groundwater abstraction, current food production/fisheries and large existing stocks/markets, covering several immediate needs. Groundwater recharge, protection and salinity are fragile, electricity has no functional island backup, and Zanzibar policy still identifies meaningful food-import dependence. The result is useful breadth with a major systemic fragility rather than durable autonomy..
Risks
- The weaker current condition in this horizon is Maintenance Resilience 3/10 — Ordinary housing, agriculture/fisheries and groundwater retain some passive/local value, but the water system depends on extensive borehole abstraction/distribution and faces salinisation/protection/monitoring problems. Electricity is imported by submarine cable and the current policy explicitly states there is no functional backup generation, so technical failure cascades are substantial.; 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: Ordinary housing, agriculture/fisheries and groundwater retain some passive/local value, but the water system depends on extensive borehole abstraction/distribution and faces salinisation/protection/monitoring problems. Electricity is imported by submarine cable and the current policy explicitly states there is no functional backup generation, so technical failure cascades are substantial.
Strengths
- One of the strongest scored dimensions is Population Capacity 10/10 — Unguja already supports more than 1.3 million residents with large-scale housing and public/commercial infrastructure, placing it in the highest credible capacity class relative to twenty survivors..
- One of the strongest scored dimensions is Sustainability 8/10 — A mature island society supporting more than 1.3 million people has extensive housing, markets, healthcare, sanitation, groundwater supply, agriculture/fisheries and electricity distribution, giving twenty people a very strong current habitat. Water-source pressure and mainland-dependent electricity prevent a 9-class rating..
- One of the strongest scored dimensions is Resource Security 4/10 — Unguja has extensive groundwater abstraction, current food production/fisheries and large existing stocks/markets, covering several immediate needs. Groundwater recharge, protection and salinity are fragile, electricity has no functional island backup, and Zanzibar policy still identifies meaningful food-import dependence. The result is useful breadth with a major systemic fragility rather than durable autonomy..
Weaknesses
- One of the weakest scored dimensions is Defensibility 1/10 — Unguja is a large, densely inhabited island with extensive coastline, towns, roads and ports. Twenty survivors cannot defend the canonical island as one perimeter, and no resort, Stone Town district or rural compound is substituted..
- One of the weakest scored dimensions is Isolation 1/10 — Sea separation from mainland Tanzania slows external walkers, but more than 1.3 million residents already live inside Unguja and the island has normal regional ferry/air connectivity. The dominant zombie-pressure source is therefore internal, making effective isolation very low..
- One of the weakest scored dimensions is Exposure Control 2/10 — The sea blocks direct mainland foot movement, but Unguja contains a very large resident population, multiple urban/rural centres, ports and a broad road network. Twenty survivors cannot monitor or funnel the island's internal movement effectively..
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
Fiji Islands
Fiji · Isolated Landmass
Fiji Islands keeps the same isolated landmass strategy, with only 0.3 points between the overall scores and closely matched isolation pressure.
Overall 3.7/10
Strongest alternative
Heligoland
Germany · Isolated Landmass
Heligoland scores 6.3 overall versus 3.3, adding a stronger isolation profile while staying relevant as another isolated landmass.
Overall 6.3/10
Wildcard rival
Fort Jefferson
United States · Fortified Structure
Fort Jefferson changes the strategy: it is a fortified structure with a isolation edge, while Zanzibar Island holds more of the sustainability advantage.
Overall 6.7/10