Grounding
Charts on the device, tide state on the layer, and a depth-aware route line. The failure is almost always a tide calculation, and the tide calculation is done for you.
Activities · Sailing · Skill 2–5 · Low to extreme risk
Charts, tides and weather. One passage plan.
From a dinghy on a lake to a Southern Ocean crossing, sailing is the activity with the deepest data requirement in the whole app — twenty-five nautical layers, because a passage plan that ignores tidal current is not a plan. It is a hope with a departure time.
01 / By the numbers
25Nautical layersENC charts, tides, currents, AIS, GRIB, ice, EEZ
3–30dOffshore passageWeeks to months for a circumnavigation
6hGRIB refreshWind forecasts on the standard model cycle
0Cellular requiredCharts and tide tables are on the device
02 / What the app enables
Pick the activity. The map configures itself.
These layers switch on together, because they are the set this activity actually needs. You can change any of them; the point is that the default is not a blank topo map.
- NOAA ENC and RNC
- Official vector and raster charts, updated weekly, cached offline by region.
- Tides and tidal currents
- Real-time predictions from NOAA stations, and the current set that decides your ETA.
- GRIB wind
- NOAA model wind on a six-hour cycle, for weather routing offshore.
- Ocean currents and waves
- Copernicus Marine: surface currents, significant wave height, period and direction.
- AIS
- Live vessel tracking, plus IMO traffic separation schemes.
- Ports and seamarks
- Harbors, marinas, anchorages, buoys, beacons and lights.
- Ice charts
- Sea ice extent and concentration for high-latitude passages.
- EEZ boundaries
- Maritime borders, because a courtesy flag is not a substitute for knowing.
03 / Failure modes
The ways this actually goes wrong.
Every activity in NavTrax carries a documented failure-mode list, and each entry names the feature that addresses it. Not a disclaimer — a design input.
Shipping collision
AIS plus traffic separation schemes on the same chart, with a watch-keeping schedule and check-in reminders.
Storm damage
Multi-model GRIB and a passage plan that treats a weather window as a route constraint rather than a comment in the log.
Medical emergency days from help
Offline medical guides, on-device triage, and a satellite SOS that reaches a staffed coordination center.
Rig or steering failure
Contingency plans generated per passage, naming the nearest port of refuge with the facilities to actually help.
04 / Practice
What the app assumes you already do.
- Passage planning
- Charts, tides, currents and GRIBs against one route line.
- Watch keeping
- Scheduled check-ins with escalation, even at sea.
- Weather routing
- Two models. Seasonal routing for ocean basins.
- Tide calculations
- Done from live station data, not a printed table.
05 / Curated kit
The gear list, scoped to this activity.
Pulled from the activity's own equipment profile and matched against the in-app store catalog. Nothing here is a generic recommendation.
ChartsOffline ENC regionsPinned per passage
CommsSatellite terminalStarlink or Iridium
CommsAIS transceiverClass B minimum
SafetyEPIRB and PLBRegistered
SafetyLiferaft and grab bagISAF compliant
WeatherGRIB downloaderOver satellite, byte-aware
MedicalOffshore medical kitPlus the offline guides
PowerSolar and hydroFor a passage, not a weekend
06 / Under the hood
How a passage plan is assembled
A passage plan is data, not optimism.
All twenty-five nautical layers are on Pro. Offline chart regions are unlimited on Elite.