Navigation tools
Speed conversions, distance tools, passage planning calculators and tidal tools.
ETA calculator
Calculate travel time from distance and speed in nautical miles and knots.
Tidal height calculator
Estimate tidal height at any time using the Rule of Twelfths or sine curve.
Anchor scope calculator
How much chain or rope to lay. Enter depth, rode type and sea state.
Air clearance calculator
Check whether your mast clears a bridge at the current tidal height.
Hull speed calculator
Theoretical maximum speed for displacement hulls from waterline length.
Speed converter
Convert between knots, mph, km/h and m/s.
Distance converter
Nautical miles to kilometres, statute miles and metres.