Nautical Calculator Pro

Nautical Calculator Pro is a professional marine navigation and voyage planning app for captains, sailors, and offshore crews. It quickly solves course, speed, distance, time, and ETA, converts between true and magnetic headings, and helps plan safe, efficient routes. Built for reliability at sea, it works offline, supports metric and imperial units, and offers fast, cockpit-friendly input. Ideal for boating, yachting, regattas, and coastal cruising with keywords like marine navigation app, boating calculator, voyage planning, ETA calculator, GPX export, offline tools. Core features include navigation calculators for CSDT and ETA with rhumb line and great circle options, magnetic and true conversion with adjustable variation plus set and drift and cross track error tools, and route planning with waypoints, vessel profiles for speed and fuel, unit conversion, offline use, and GPX export.