The Map is not a live radar picture. It shows the most recent AIS transmission the app has managed to collect for your yacht, which can be seconds old or days old depending on where the vessel is. The Last update line in the vessel's details panel always tells you which.
Why there are gaps
AIS is a short-range radio broadcast. It is picked up by receivers ashore and on other vessels, so a yacht is reported often while it is near a busy coast and can go completely silent once it is well offshore or in a quiet corner of the world. Nauticare can only show what was received; it has no way to fill in a position nobody heard.
Reception is not the only reason a position can go stale:
- the AIS transponder is switched off, or is transmitting at reduced power in port
- the vessel is somewhere with no receiver in range
- the yacht's MMSI in Nauticare does not match the one the transponder is broadcasting
A long straight leg on the track, or a position that has not moved for days, is nearly always one of these rather than a fault in the app.
Reports do not always arrive in the order they were sent. If one turns up carrying a timestamp older than the position already stored, it is discarded rather than applied, so the pin never jumps backwards to somewhere the yacht had already left.
Top-ups from a paid AIS service
Besides listening for broadcasts, Nauticare can top a yacht's position up from a paid AIS data service. Top-ups are switched on per vessel by Nauticare, so not every yacht receives them, and they come in two strengths:
- Hourly — for a topped-up vessel whose plan includes Map (hourly update). Once an hour the app checks how old the stored position is, and only if nothing has arrived for roughly the last hour does it fetch a current one.
- Daily — every topped-up vessel, whatever its plan, gets a check once a day in the morning, which fetches a position if none has arrived in the previous four hours.
A yacht that is already being heard regularly is left alone either way. Where the hourly top-up is running, the position rarely falls much more than an hour behind while the vessel is within any AIS coverage at all. Without a top-up, how current the map is depends purely on what happens to be received. No option can produce a position for a yacht that is genuinely out of range of every receiver.
If you are not sure whether a vessel is on the Map (hourly update) plan or receives top-ups, your company administrator can check with Nauticare.
Refreshing what you are looking at
The page does not tick along by itself while you watch it. It loads the latest stored position when you open it, and loads it again when you come back to the browser tab after being away — so switching to another tab and back, or reloading the page, is enough to pick up anything new. Leaving the map open in the foreground for an hour will not, on its own, move the pin.