How It Works
No internet needed
Shares
Device with GPS
A cellular iPad, iPhone, or Android with a real GPS fix. It broadcasts its position over Wi-Fi.
Receives
Wi-Fi-only device
An iPad/tablet with no GPS. It connects and shows the shared position as its own.
The sharing device runs a tiny local GPS signal over your Wi-Fi. The other device picks it up directly — no cell signal, internet, or cloud. Perfect for getting another season out of a Wi-Fi-only iPad.
What You Need
3 things
A device with GPS
The sharing device — a cellular iPad, iPhone, or Android that already gets a good position.
The Wi-Fi-only device
The receiving device with no GPS of its own — the one you want to put on the map.
One Wi-Fi network
Both devices on the same Wi-Fi — boat router, Starlink, or a phone hotspot. Bristol Maps on both.
1
Turn On Sharing
On the GPS device
Open the NMEA section
Tools tab → Settings, scroll to NMEA Connections.
"Share my GPS over Wi-Fi"
Toggle it on. The device now broadcasts its position to the network.
Keep the app open
It only shares while Bristol Maps is open and has a live GPS fix. Don't background it.
2
Find & Connect
On the Wi-Fi-only device
Open the same screen
Tools → Settings → NMEA Connections, under the "GPS shared on this Wi-Fi" heading.
Spot your other device
It appears automatically as "BristolMaps <name>" with its IP address.
Tap the green Connect
Tap Connect. That links the two devices and turns on location updates for you.
3
Confirm It's Live
On the Wi-Fi-only device
"Enable NMEA Location Updates" is on
Connect switches this on automatically. If your map doesn't move, this is the toggle to check — make sure it's on.
Watch the map jump
Within a few seconds the map snaps to the shared position and follows it. You're done.
Auto-discovery not finding it? Page 2 covers connecting by hand (enter the IP and port 10110), troubleshooting, and the limits worth knowing.
Connect by Hand (if it's not auto-discovered)
4 steps · receiving device
Some boat routers hide devices from each other ("AP / client isolation"), so auto-discovery comes up empty even though both devices are online. You can always connect by typing the address in.
1
Find the sharing device's IP
On the GPS device, the "Share my GPS over Wi-Fi" status line shows its address — or read it from that device's Wi-Fi settings. It looks like 192.168.x.x.
2
Add a connection
On the Wi-Fi-only device: Tools → Settings → NMEA Connections → "+ Add NMEA Connection".
3
Enter host & port
Host = the IP from step 1. Port = 10110 (the GPS-sharing default). Give it any name and Save.
4
Connect & enable
Tap Connect on the new entry, then confirm "Enable NMEA Location Updates" is on. The map adopts the shared position.
Troubleshooting
"No devices sharing GPS found yet."
Check both are on the same Wi-Fi (not one on cellular). Confirm "Share my GPS over Wi-Fi" is on and that app is open. If the network isolates devices, connect by hand (above).
Connected, but the map won't move
On the receiving device, turn on "Enable NMEA Location Updates". The position can arrive without this on — but the map won't follow it until it is.
Position froze or went stale
The sharing device lost its GPS fix or got backgrounded. It only broadcasts with a fresh fix while the app is open — bring it back to the foreground.
Heading looks wrong when stopped
Heading comes from movement (course over ground), not a compass on the receiving device. It settles once you're underway.
Good to Know
Free & offline
Runs entirely over local Wi-Fi. No internet, cell signal, or extra subscription needed to share between your own devices.
Keep the sharing app open
Sharing runs only while that app is in the foreground. Lock the screen or switch apps and it pauses until you return.
A hotspot works too
No boat router? Turn on a phone hotspot and join both devices to it — same idea, same steps.
This is device-to-device, on your boat. To see your fleet's boats on the map, that's a different feature — group location sharing over the internet. See the Fleet guides or bristolfleet.com.
