WindCalc vs TrueWind

This app converts apparent wind to true wind or ground wind, depending on the inputs for vessel speed and heading. This is a computation needed daily by sailing vessels underway and by ships reporting weather to national agencies. Use SOG and COG from the GPS for speed and heading to get the "true wind" used in official forecasts (sometimes called "ground wind") or use true heading derived from compass heading and knotmeter speed to get the" true wind" used on sailboat’s polar diagrams (sometimes called "water wind). Likewise this app does the reverse computation, true wind to apparent wind, so a mariner can forecast expected apparent wind based on a forecasted true wind change and known true wind boat speeds from a polar diagram. This allows mariners to plan for the sails needed and the courses available to them when the new wind appears. The app is designed with a simple, clean interface for efficient use.

TrueWind is a sailing and nautical weather app built for sailors, skippers, regatta racers, and watersport enthusiasts. Wind, current, tide, waves, weather, and NWS marine alerts, all in one clean app. NEW: RACE REMINDERS Add your weekly race once and TrueWind keeps it ready. See wind, current, and tide for your exact race window on one screen, watch how the wind builds or fades from start to finish, and get notified when conditions change significantly. A Home Screen widget counts down to your next race with the latest conditions. WITH TRUEWIND YOU CAN VIEW - Wind direction, speed, and gusts - Wind shifts over time - Tide station data, including high and low times and spring tides - Current station data, including flood and ebb, for better timing - Wave details, including height and wavelength - NWS marine alerts, including storm, gale, and other marine warnings - Race conditions for your exact start and finish times - Home Screen widget for your next race BUILT FOR REAL SAILING DECISIONS From Nantucket sailing days to Tuesday night club racing, weekend regattas, and everyday boating, TrueWind brings the marine conditions that matter into one fast, easy-to-read view, without the clutter of a general weather app. Plan with confidence. Sail with better timing.