Plan a drawn sea route in nautical miles
Estimate distance and time while keeping navigation decisions separate.
Draw the intended water route
Add waypoints along the route rather than drawing one straight line from departure to arrival. Each segment contributes to the total. Inspect the route legs to find an accidental shortcut across land or an incorrectly placed waypoint. The tool does not detect these hazards automatically.
Estimate travel time
One nautical mile is exactly 1,852 metres and one knot is one nautical mile per hour. Divide route distance in nautical miles by average speed in knots. For example, 14 nautical miles at 7 knots gives 2 hours. Account separately for stops, current, weather and reduced-speed areas.
Choose a useful background
The sea-map option shows seamarks where OpenSeaMap has coverage. Satellite imagery can help you recognise shorelines and structures, but neither option establishes safe water depth or current passage conditions. Compare the same sample route at several speeds in the method tests.
Before travelling
Use current official charts, notices, weather, depth information and local rules. Check vessel limitations, route alternatives and appropriate safety margins. A copied waypoint list or a measured map line is not a navigation clearance or a guarantee of safety.