Updated 2026-07-31
Boat Speedometer and Knots Guide
Boat speed is often shown in knots. A GPS boat speedometer can estimate speed over the ground from your phone.
Why boats use knots
Knots are tied to nautical miles and are the standard speed unit in marine navigation and boating.
Using GPS on a boat
Keep the phone dry, secure, and where it has clear sky view. Choose boat mode and use kn as the primary unit.
Convert when needed
Use the knots to km/h converter when you want to compare marine speed with road or travel speeds.
Set knots as the default
Boat users usually read speed in knots. Choose boat mode and select kn so the main speed reading matches marine expectations.
GPS speed on water
Phone GPS estimates movement over the ground. Current and wind can make that different from how fast the boat moves through the water.
Safety reminder
zigmaty is a simple speed utility, not a certified navigation, marine, or safety instrument. Use proper marine equipment for navigation decisions.
FAQ
Use a phone as a boat speedometer, understand knots, and convert boat speed between knots, km/h, mph, and m/s.
What is one knot?
One knot is one nautical mile per hour, equal to 1.852 km/h.
Can a phone measure boat speed?
Yes, when GPS signal is available.
Is zigmaty a navigation instrument?
No. It is a simple speed utility, not a certified marine navigation device.
Should boat mode use km/h or knots?
Boat mode defaults best to knots because knots are standard for marine speed.
Can GPS measure current?
No. GPS measures your movement over the ground, not the water current by itself.
Can I use it offshore?
Only as a simple speed reference. Do not use it as a navigation instrument.