How the pieces fit together
Each agent has one job and hands on an explicit contract. A manager chooses the pipeline and refuses an ineligible pick; a critic re-derives the result before it is delivered, and issues a completeness certificate only if the search actually finished.
Found live, classified before it is trusted
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Sea ice
US National Ice Center · USNIC Arctic chart archive (NSIDC G10013)
- primary-government
- high confidence
- 100.0% coverage
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Bathymetry
NOAA NCEI · DEM mosaic (DEM_all ImageServer)
- primary-government
- medium confidence
- 100.0% coverage
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Waves & weather
Open-Meteo · Marine (wave height) + Forecast/Archive (wind gusts)
- third-party-aggregator
- medium confidence
- 99.0% coverage
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Ecosystem
NOAA Fisheries · Essential Fish Habitat, Eastern Bering Sea
- primary-government
- high confidence
- 100.0% coverage
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Community & subsistence
Alaska DCRA / BOEM · subsistence-designated communities (points); BOEM use areas (polygons)
- primary-government
- high confidence
- 100.0% coverage
Alaska DCRA map services BOEM Offshore Subsistence Use Areas
Exposure measured, and two lines a vessel does not cross
Ecological cost is mapped habitat extent — Essential Fish Habitat, ESA critical habitat, ice-seal habitat — carried as equal-weighted categories, because ranking one habitat above another is not the agent's call. Ice difficulty comes from the ice chart; sea state from the wave model. Where the wave model has no sample the gap is decomposed into measured, ice-attributed and unknown: an absence the system can explain is not the same as one it cannot, and unmeasured water is drawn as a gap, never as a zero.
Ice standoff — for declared fuel or hazardous cargo
A spill under or against sea ice is the worst case in this ocean: ice blocks mechanical recovery, traps oil against the underside, and carries it far from the release point. A vessel declaring such cargo can be held a chosen distance off charted ice — and what counts as ice is chosen too: any charted ice, the most protective reading; ice at or above 3/10 concentration, roughly where booms and skimmers stop being viable; or thick and old ice only, at 0.7 m stage thickness, in the spirit of the Polar Code's POLARIS scheme.
Shore standoff — for a declared large vessel
Held a chosen distance off the unnavigable margin: land, or water shallower than that vessel's own draft plus margin. The ground is nearshore presence, not wake — marine mammals concentrate there, subsistence hunting and travel happen there, a release there has the least drift time before it reaches shore, and the survey is thinnest there. The precedent is the IMO's Bering Strait Areas To Be Avoided, in force since December 2018 around St. Lawrence, King, Nunivak and the Diomedes, which trigger on vessel size at this same distance scale.
Neither standoff is a cost
Cells within the chosen distance are removed from the passable area before any route is generated, so "too close" is off the graph rather than merely expensive. Port approaches are exempt inside 15 km, or no voyage could begin. No distance is ever defaulted: unanswered means no standoff is applied and the run says so, while an explicit no standoff is recorded as the person's decision. Every removal, every exemption, and every standoff that could not be attached is written to the ledger — a protection that silently fails is worse than none, because it is trusted.
Community burden is a definition someone chooses
After the routes exist, a separate lens measures nautical miles of route within a stakeholder-selected radius of a community — modelled proximity burden, which is not harm, not harvest, and not subsistence-use exposure.
Four formulations are offered and none is called fairer. The radius has no default. Adaptive capacity is marked unavailable on measured grounds, and its weight is not redistributed. No community is given an intrinsic vulnerability label.
The routes worth choosing between
What comes back is not one route but the set that survives dominance: each best at something, none best at everything. The heaviest line is preference-optimal under the priorities that were actually stated, not under a default the agent picked.
