PNW Current Atlas vs WindCalc

The PNW Current Atlas brings a fast and easy way to view Pacific Northwest current prediction charts for the Juan de Fuca Strait / Strait of Georgia regions on your mobile device. This includes complete coverage of the US San Juan Islands, the Canadian Gulf Islands, and the Eastern Juan de Fuca Strait and more. This digital current atlas includes predictions for the current year with free yearly updates so that you never have to buy a reference or look-up table ever again. Features: ◆ View any date/time within a tide cycle, past or future (within the current year) ◆ Fully corrected for Daylight savings time ◆ Easily jump to the prediction closest to Now with a single tap ◆ Easily move forwards or backwards through prediction time by tapping or swiping ◆ Zoom into predictions to see more detail ◆ Works offline - no Internet connection needed! ◆ Includes all predictions for the current calendar year with free yearly updates ◆ and more...

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.