WindCalc vs True Wind Pro

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.

True Wind Pro is a precise nautical wind calculator and training tool designed for sailors, navigators, and marine students. Convert apparent wind into true wind direction and speed using the classic nautical-school vector method — clearly visualized and easy to understand. Key Features • True wind direction (TWD) and speed (TWS) calculation • Apparent wind (AWA / AWS) support • Atmospheric pressure readings using the iPhone’s built-in barometer sensor • Pressure history with date and time • Easy access to pressure, wind direction, and wind force values for entering into the ship’s deck logbook on the bridge • Interactive radar and wind triangle plot • Step-by-step vector construction (nautical-school method) • Reverse calculator: find heading for a target apparent wind angle • Beaufort scale interpretation • Clean, distraction-free interface optimized for marine use Designed for Learning & Practice True Wind Pro doesn’t just give you numbers — it shows how the result is constructed. Perfect for sailing schools, exam preparation, and real-world navigation planning. The app also helps with practical bridge routines by making atmospheric pressure, wind direction, and wind force easy to check and enter into the ship’s deck logbook. Free & Pro You can perform 5 free calculations to try the app. Unlock True Wind Pro – Lifetime to get unlimited calculations forever with a one-time purchase. No subscriptions. No ads. Ideal for sailors, skippers, students, navigators, and anyone who wants to truly understand wind mechanics at sea.