About this reference
What the Blue Water Index shows, and what it cannot know
The Blue Water Index is an independent reference assembled from published open sources. It connects individual hulls, ship classes, bases, systems, future programmes and notable reporting without presenting uncertain conclusions as official fact.
Fleet placements were reviewed through . Curated News and Future Fleet show their own review dates. Individual ship records retain the date on which that placement was last checked.
Scope
The in-service fleet covers PLAN surface combatants, amphibious ships, replenishment ships and submarines represented in the master roster. Ships still building, fitting out or on trials remain in Future Fleet until commissioning, so they are not counted as in service and are not assigned a fleet or base prematurely.
Each navy is covered to its own published scope, and those scopes differ. The Chinese fleet here includes its replenishment ships; the American one does not, because US replenishment is run by Military Sealift Command, which sits outside the battle-force scope used for that navy. Comparing the two totals directly would therefore understate US logistics. The confidence models differ too: Chinese placements often rest on inference and carry a graded confidence badge, where American home ports are published outright and almost all sit at the highest tier.
Two different kinds of uncertainty
Basing confidence
High means direct official or unambiguous named-hull evidence. Medium means a sourced placement with limited corroboration or specificity. Low means weak or unresolved evidence. Assumption is categorically different: a probabilistic placement from fleet and class patterns, not a direct sighting.
Hull identity
An inferred identity label means the pennant number is documented for the class, but no source assigns that particular hull to the fleet or base shown. Identity and basing are kept separate because one can be well supported while the other remains uncertain.
Why some hulls stay unnamed
Thirteen in-service slots remain aggregate records because no public pennant number can be matched to them responsibly. They stay visible as gaps in the fleet rather than being omitted or filled with invented identities.
Sources and judgement
Ship records link directly to the sources behind their basing claims. Class specifications carry their own source list. Chinese state media is included where it establishes an official claim, but it is labelled so that claim is not mistaken for independent observation. Future Fleet progress percentages are analytical estimates from observable build stage, never reported PLAN figures.
Limitations
- Open-source reporting is incomplete, uneven and can become stale quickly.
- A deployment, shipyard visit or exercise does not always establish a permanent home port.
- Submarine identities and locations are especially opaque.
- The map combines named facilities where public reporting does not reliably distinguish adjacent sites.
- This tool is independent and is not affiliated with any navy or government.
Every confidence badge can be opened for its reasoning. Where the evidence does not support a precise answer, the interface is designed to show the uncertainty rather than hide it.