A marine weather app earns its place by answering three questions: how hard will the wind blow, what will the sea state feel like, and when is the best time to go. This guide compares the best marine weather apps in 2026, what each is actually good at, which are free, and the two numbers most boaters read wrong.
- Windy is the best free way to visualize multiple forecast models on one map.
- PredictWind is the offshore standard: weather routing and departure planning built for sailors, at a price.
- NOAA marine forecasts and buoy observations are free, official, and underrated for US waters.
- Wave period matters as much as wave height; gusts matter more than average wind.
- Departure scanners turn a forecast into a decision by rating every leaving time along your route.
#Windy
Windy is where most boaters should start. It overlays wind, gusts, waves, swell, and rain on a beautiful animated map, and its killer feature is switching between forecast models (ECMWF, GFS, ICON and more) to see whether they agree. The core is free with a paid tier for higher-resolution updates. It is a visualization tool, not a marine decision engine: it shows you the weather but does not know your boat or route.
#PredictWind
PredictWind is the serious offshore tool: proprietary and top-tier global models, weather routing that bends your course around systems, departure planning that compares leaving on different days, and satellite integration for mid-ocean updates. Cruisers crossing oceans standardize on it and pay real subscription money for the privilege. For coastal day boating it is more machine than most people need.
#NOAA marine forecasts and buoys (free, US)
For US waters, NOAA publishes zone-by-zone marine forecasts written by humans, plus live buoy observations showing what the sea is actually doing right now. Both are free. Checking a nearby buoy against the forecast before you leave is the oldest reality check in boating and it still beats any app graphic.
#Buoyweather and point forecasts
Buoyweather sells simple point forecasts: pick a spot on the ocean, get a marine forecast table for it. It is less visual than Windy and less capable than PredictWind, but the table format is easy to read at the dock and it covers offshore points plainly.
#Departure scanners: forecast to decision
The newest category closes the gap between seeing weather and choosing a departure. The Marine OS route planner includes a departure scanner: it takes your actual route and speed, checks every leaving time over the next 72 hours in 6-hour steps, evaluates each point of the route at the hour you would reach it, and rates every window from Calm to Severe using wind, gusts, wave height and period, with your choice of ECMWF, GFS, or ICON models. One click sets the best departure on the route. It runs in the browser and works worldwide on the open Open-Meteo forecast data.
First, wave period: 1.5 meter waves at 11 seconds are a gentle swell, the same height at 5 seconds is a washing machine. Second, gusts: an 12-knot forecast with 25-knot gusts is a gusty day, not a 12-knot day. Any app that hides period or gusts is hiding the story.
Marine OS is marina management software, and the Marine OS route planner shows wind, gusts, waves and comfort ratings along your route at your arrival times, plus the departure scanner described above. It reads the same open forecast data Windy visualizes, applied to your specific trip.
Scan 72 hours of departures against your route
Plan the route, pick a model, and let the departure scanner rate every leaving time by the worst conditions you would meet along the way.
#Frequently asked questions
Frequently asked questions
Visualize with Windy, verify with buoys, and decide with a departure scan. Method in the weather window guide; the full app stack in best boating apps.
Get the next post in your inbox
Monthly marina operations briefing. 2,400+ subscribers.