PredictWind Offshore: The Complete Guide for Mariner Weather RoutingPredictWind Offshore is a comprehensive weather-routing and marine-forecasting platform built for sailors, offshore racers, commercial mariners, and passagemakers. It combines high-resolution model data, proprietary ensemble techniques, advanced routing algorithms, and an easy-to-use interface to produce route options that optimize time, fuel, and safety. This guide explains how PredictWind Offshore works, its key features, how to use it effectively, common workflows, strengths and limitations, and tips for integrating it into real-world passage planning.
What PredictWind Offshore does
PredictWind Offshore provides:
- High-resolution wind, wave, current, and pressure forecasts tailored for offshore and bluewater sailing.
- Weather routing that calculates optimal courses based on vessel performance, safety constraints, and user preferences.
- Ensemble and model comparison tools to quantify forecast certainty and identify areas of risk.
- Downloadable GRIB files and offline functionality so mariners can use forecasts when disconnected.
- Alerts and notifications for critical weather events along a planned route.
Core components and data sources
PredictWind Offshore relies on several data inputs and internal systems:
- Numerical Weather Prediction (NWP) models:
- Global models (e.g., GFS, ECMWF alternatives depending on availability).
- High-resolution regional models that PredictWind runs or licenses to capture coastal and local features more accurately.
- Ensemble modeling:
- PredictWind’s ensemble blends multiple runs and models to present probabilistic views—useful for identifying forecast spread and uncertainty.
- Wave and current models:
- Integrated wave forecasts (swell, sea state) and ocean current guidance to compute route impacts.
- Routing engine:
- A performance-based optimizer that uses your vessel’s polars or speed predictions to produce fastest, safest, or fuel-efficient routes.
- GRIB engine and mobile/offline tools:
- GRIB downloads with selectable models and resolutions, plus offline charting and routing for use without internet.
Key features and interfaces
PredictWind Offshore is available via web and mobile apps and includes specialized tools:
- PredictWind Offshore (web app): Full routing console with map overlays, routing options, ensemble views, and export functions.
- PredictWind Offshore App (iOS/Android): Mobile routing, GRIB downloads, offline charting, and notifications.
- PredictWind Desktop: Tools for GRIB visualization and detailed route planning (depending on subscription).
- Vessel-specific routing: Enter boat type, polars, fuel consumption, and safety parameters (max heel, storm avoidance zones).
- Weather Routing Modes:
- Fastest route (minimize time).
- Fuel-efficient / motoring-aware routes.
- Safe routes that avoid certain wind strengths, sea states, or proximity to hazards.
- Ensemble and model comparison screens: Visualize multiple model runs and probability cones.
- Alerts: POIs and route watches for wind, sea state, or system changes.
- Export options: KML/GPX for plotting on chartplotters, downloadable GRIBs for other software.
How routing works: inputs and options
To get an accurate routing plan, PredictWind uses a combination of user inputs and model data:
- Vessel data:
- Polars (or default boat types), displacement, engine power, fuel burn, and hull type.
- Constraints: maximum heel, preferred VMG strategy, motoring thresholds.
- Route definitions:
- Start and end points, waypoints, and mandatory routing corridors or exclusion zones.
- Time window:
- Departure windows (specific time or flexible range) and arrival preferences.
- Weather preferences:
- Avoidance of particular wind ranges, swells, or storm cells; allowance for motorsailing.
- Optimization criteria:
- Shortest elapsed time, minimum fuel, or balanced comfort/safety.
The routing engine runs the chosen meteorological model(s) over the route and evaluates many possible tracks against the vessel performance model to produce an optimal course. Ensemble runs can be processed to show alternative routes and probabilistic arrival windows.
Practical workflow: plan a passage step-by-step
- Prepare vessel profile:
- Upload polars or choose a similar boat profile; set motoring fuel burn and safety limits.
- Define route:
- Enter origin, destination, and any intermediate waypoints. Mark exclusion zones if required.
- Select models and resolution:
- Choose high-resolution regional models where available for coastal work, or ensembles for offshore uncertainty awareness.
- Set departure window:
- Use a fixed departure time for one-off passages or a flexible window to compare options.
- Run routing:
- Generate fastest/fuel-efficient/safe routes. Review route legs, estimated times, and key weather along the track.
- Inspect ensembles and model comparisons:
- Look at agreement or divergence between models—wide spread = higher uncertainty.
- Download GRIBs and route export:
- Save files for onboard systems and offline charts. Export GPX/KML to plot on chartplotters.
- Monitor and update:
- Re-run routing as forecasts update, and watch alerts for changes that affect safety or ETA.
Interpreting outputs: charts, polars, and ETA
- Route track and legs:
- The map shows the computed track, waypoints, and alternate routing lines from different model runs.
- ETA and arrival windows:
- Single-model routes give one ETA; ensemble outputs provide a probabilistic arrival window—useful for scheduling crew changes or port arrival windows.
- Weather overlays:
- Wind barbs, wind speed shading, wave heights and direction, current vectors, and pressure fields.
- Polars and VMG:
- The routing output references your polars to determine optimal sail angles and whether VMG or direct-course strategies are used.
- Risk indicators:
- Areas with rapidly changing forecasts, high seas, or strong currents flagged for review.
Strengths
- High-resolution and regional modelling provides superior coastal detail compared with coarse global models.
- Ensemble capabilities help quantify forecast uncertainty and plan for contingency.
- Integrated wave and current data make routing more realistic for passage time and safety.
- Flexible vessel profiles and optimization criteria (time vs fuel vs safety).
- Offline and GRIB support for disconnected navigation.
Limitations and caveats
- Forecast uncertainty still exists—ensembles reduce but don’t eliminate risk.
- Model biases in certain regions (complex coastlines, tropical systems) can affect accuracy; local knowledge remains essential.
- Routing quality depends on accurate vessel polars and realistic motoring/fuel inputs.
- Real-world constraints (traffic separation schemes, port availability, and on-deck issues) aren’t always fully modeled.
Best practices and tactics
- Regularly update routes as forecasts change—run daily or twice-daily during critical passages.
- Use ensemble spread to set conservative margins for arrival windows and fuel planning.
- Validate polars by comparing predicted vs observed speeds on typical legs; refine vessel profile accordingly.
- Combine PredictWind routing with local pilot charts and meteorological bulletins for coastal passages.
- For ocean racing, run multiple model/routing combinations and plan alternative start windows.
- Keep GRIBs and exported routes onboard for offline re-routing.
Example scenarios
- Bluewater passage: Use a 72–168 hour ensemble routing to select a departure window with the most favorable winds and smallest uncertainty band.
- Coastal hopping: Use high-resolution regional models to pick routes that avoid local wind shadows and eddies.
- Motoring-heavy passage: Input fuel burn and motoring thresholds to find the balance between sailing and engine use that minimizes fuel while keeping schedule constraints.
- Offshore race: Run multiple optimizations with different weather models and conservative safety buffers; watch for strategic shifts as systems evolve.
Integrations and device support
- Chartplotters and navigation suites: Export GPX/KML for plotting; some systems accept GRIB overlays.
- Mobile: Full offline GRIB viewing and routing in mobile apps for on-watch decision-making.
- Third-party tools: GRIB downloads and exported routes are usable in many marine navigation and passage-planning programs.
Cost and subscription tiers (general guidance)
PredictWind typically offers tiered subscriptions: basic GRIB access and live forecasts at lower tiers, with full routing, ensemble capabilities, and high-resolution regional models at higher tiers. Choose based on voyage type: occasional coastal cruising needs differ from competitive offshore racing or frequent commercial passages.
Conclusion
PredictWind Offshore is a powerful tool for mariners who need detailed, performance-aware weather routing. Its strengths are high-resolution forecasts, ensemble analysis, and flexible vessel-specific optimization. To get the most from it, maintain accurate vessel data, routinely re-run routes as forecasts update, use ensemble outputs to manage uncertainty, and combine the software’s guidance with local seamanship and navigation practices.
If you want, I can:
- Create a shorter checklist for pre-departure routing with PredictWind Offshore.
- Draft an onboard SOP (standard operating procedure) for updating routes while underway.
- Produce a sample route setup (with example polars and settings) for a specific yacht type—tell me your boat class and passage.