Getting Started
From two waypoints to a captain-ready brief.
A walkthrough of your first voyage analysis on NaviSight — what to click, what each tab shows, and how to read the result. Plan on five minutes the first time, less after that.
Walkthrough
Five steps to your first analysis
Follow these in order. After you've done it once, the whole flow takes well under a minute.
Configure your vessel
Open Vessel Profiles and create a profile with your boat's LOA, beam, draft, displacement, cruising speed, and fuel capacity. NaviSight uses these numbers to tune every risk and comfort score — a 38 ft cruising sloop and a 90 ft motor yacht do not see the same routes for a reason.
- If you don't have time to fill out a full profile, the voyage page exposes a set of operating presets (recreational sail, recreational power, small commercial, large commercial) that work as a sensible default.
- Vessel profiles are stored in your browser's localStorage. They never leave the device.
Set origin and destination
On the Route Analysis page, click the map or type into the search field to set your departure and arrival waypoints. You can add intermediate waypoints for multi-leg voyages — each leg is solved independently with its own forecast window.
- Waypoints can be reordered or removed inline. The great-circle line between them is shown as a dashed reference, not a route recommendation.
- Click any blank water on the map to fetch the live wind / wave / temperature point forecast for that location.
Choose your departure window
Pick a departure date and time. NaviSight pulls the forecast for the full transit horizon, so you do not need to guess how long the trip will take — the engine resolves transit time per segment from the vessel's polar / power curve and the en-route weather.
- If the predicted ETA stretches past the reliable forecast horizon (typically ~10 days), the late legs will be flagged with a low-confidence badge.
Run the analysis
Press Analyze. NaviSight runs twenty Dijkstra routes — four optimisation objectives (Safe / Fast / Comfortable / Fuel-Efficient) across five weather models (GFS, ECMWF, ICON, UKMO, ARPEGE) — plus a wave-model and ocean-current overlay against the same path.
- Analysis typically completes in 10–30 seconds depending on voyage length. Coastal hops are faster than ocean crossings.
- All twenty routes are kept — the four you see by default are the per-objective consensus routes; the underlying five-model spread is one click away in the Routes tab.
Read the map
The four objective routes are drawn in distinct colours, with a translucent uncertainty cone showing where the five-model ensemble agrees and disagrees. Weather overlays — waves by default, switchable to wind, pressure, currents, SST, and more — render as native WebGL tiles from our self-hosted forecast pipeline.
- The legend at the top-right of the map controls overlay selection and per-overlay weather model. Wind / current overlays animate via a GPU particle system.
- Click any segment of any route to see the forecast at that point — wind, Hs, period, current, temperature, and a per-segment risk breakdown.
Reading the result
What each tab shows
The right-hand panel after analysis is split into five tabs. Each one answers a different planning question — here's how to use them.
Routes
The four objective routes side-by-side, each with ETA, average Hs, average wind, fuel burn, comfort score, and risk score. Expand any objective to see the five underlying model routes that produced the consensus.
- Per-objective summary cards with ETA distribution bars (P10 / P50 / P90)
- Model agreement badges — high / medium / low consensus
- Per-segment timeline with risk and comfort sub-scores
- Click-to-select interaction that drives the map cone, the recommendation panel, and the report selector
Risk & Charts
Quantitative breakdowns of every score the engine emits. Risk decomposition (wind, wave, current, regulatory, seakeeping), comfort decomposition (MSI, slamming probability, parametric-roll exposure), departure-window forecast paired side-by-side with the annual climatology heatmap.
- Risk Breakdown chart — see exactly which sub-component drives the headline number
- Departure Windows panel — five-day forecast feasibility next to monthly historical climatology
- Forecast confidence banner reflecting the five-model spread
Recommendations
Plain-English guidance for the captain. Departure-window recommendation, model-spread interpretation, segment-by-segment warnings (heavy weather, slamming risk, parametric-roll exposure, broaching window), and a current-month historical context card.
- Forecast Confidence panel with explicit "high / medium / low agreement" verdict
- Per-objective five-model forecast comparison (selectable via dropdown)
- Historical Climatology card — current-month feasibility %, average Hs and wind, best / worst months for the route
Compliance
Regulatory exposure — ECA / SECA in-zone time, fuel-sulphur implications, and the regulatory_score that feeds the risk surface.
- ECA / SECA polygons on the map (when the overlay is enabled)
- Per-route in-zone NM and percentage of voyage spent inside emission-control areas
- Implications for fuel selection if the route is fuel-burn-optimised
Downloads
The export hub. Choose which objectives to include, whether to expand the per-objective five-model breakdown, and whether to attach the segment table and historical heatmap. Then generate a printable PDF or download GPX 1.1 files for the chartplotter.
- PDF report with vessel-aware header, segment timeline, ETA bars, ECA / SECA exposure, and a reference legend
- GPX 1.1 export per objective and per model — load into OpenCPN, B&G, Garmin, or any standards-compliant chartplotter
- Raw analysis JSON for downstream tooling
FAQ
Common questions
The questions we hear most often from professional mariners and experienced cruisers.
How accurate is the weather data?+
Sources are the same global forecast models used by national weather services and most commercial routing tools — GFS (NOAA), ECMWF IFS, ICON (DWD), UKMO, ARPEGE (Météo-France), WaveWatch III, and HYCOM. Skill is excellent in the first 72 hours, good through day 5, and degrades after day 7. Past day 10 we mark the late legs with a low-confidence badge. NaviSight does not adjust, infill, or smooth the raw forecasts — when the models disagree, you see the disagreement directly as a wider uncertainty cone.
What does the risk score actually mean?+
It is a forecast-conditional probability of a casualty event (capsize, grounding, foundering, collision, machinery failure) derived from real-world maritime incident records. Curves are fit using sigmoid and Weibull functional forms so rare-but-severe regimes are handled correctly. The score is empirical, not heuristic. It is a planning aid, not a guarantee.
Can I use NaviSight for offshore passages?+
Yes. The engine handles ocean crossings — the navigation grid scales with voyage length and the forecast horizon extends through the full transit. For passages whose ETA exceeds ~7–10 days, the late-leg recommendations are automatically marked with a low-confidence badge so you know to re-run the analysis as the departure window approaches and the forecasts firm up.
How is NaviSight different from PredictWind / Windy / Savvy?+
Two differences. (1) Risk scoring is empirically calibrated against real-world incident data, not arbitrary thresholds. (2) Comfort and stability scores come from first-principles physics (ISO 2631-1 MSI, Ochi–Motter slamming, GZ curves, Kwon 2008 wave-added resistance) rather than categorical sea-state buckets.
Why do I see four routes instead of one?+
Different captains optimise for different things. The Safe route minimises composite risk. The Fast route minimises ETA. The Comfortable route minimises crew motion exposure (RMS vertical acceleration). The Fuel-Efficient route minimises burn. They are usually similar in benign weather and meaningfully different when conditions are mixed — that's where the routing engine earns its keep.
What if the five models disagree?+
The uncertainty cone widens, the agreement badge drops to medium or low, and the Recommendations tab calls it out explicitly. Disagreement is most common ahead of a developing low or in the deep tropics. The honest answer in those cases is "the atmosphere is harder to predict here" — NaviSight surfaces that fact rather than averaging it away.
Does NaviSight tell me when to leave?+
The Recommendations tab summarises the next five-day departure window against your route, paired with the annual climatology for the current month so you can sanity-check whether the forecast is unusually favourable or unfavourable for the season. The decision to depart remains yours.
Is there a mobile or tablet experience?+
Yes — the voyage page is responsive down to phone widths. The map, route cards, and recommendation panel all reflow. For sustained planning we recommend a tablet or desktop because the map legend and route comparison benefit from screen real estate.
Where does my data go?+
Vessel profiles are stored in your browser's localStorage. Voyage analyses are computed server-side but are not persisted under your account today (saved-analysis storage is on the roadmap). API keys for upstream weather providers are server-side only — your browser never sees them.
I think the engine is wrong about something. What do I do?+
First, click the segment in question and read the per-segment risk and comfort sub-scores — the headline number is composed from a stack of sub-components and the issue is usually visible there. If you still believe the score is off, file an issue on the GitHub repo with the route, the timestamp, and what you expected. Every coefficient is exposed in a versioned config file precisely so this kind of feedback can drive recalibration.
Ready to plan a passage?
Set your waypoints, pick a vessel profile, and run the analysis. Twenty routes, an uncertainty cone, and a captain-ready brief in return.