Can't get speed or heading data below 4.5 knots with my GPS on Coastal explorer

Hello I’ve recently purchased a Panasonic toughbook with built in GPS to run Coastal explorer on. I’m getting Coastal explorer to pick up the data from COM3 port and it is getting a fix. Here’s where it gets weird, when I’m sailing less than 4.5 knots speed data dissapears and so does my heading info. This is with the laptop on deck, still getting a fix and updating Lat and Long. The boat icon is still tracking but it’s a bit jumpy, just no heading data and no speed.

Once I’m above 4.5 knots I get a nice smooth heading readout, COG line and Speed data. I’ve tried this both in my car and boat.

I’ve contacted the company who sells the tough books to ask about the GPS and they had me download an open source GPS viewer to see how well the GPS is working, and it works fine, picks up American and GNSS Satellites no problem and gets a fix relatively quickly.

I’m a bit stumped on this one.

Hi there,

This is generally expected with a normal GPS, for a true heading at all times you would need a satellite compass that involves 3 separate sensors to triangulate your exact heading. You should still receive a speed and cog even when not moving which is odd. For this kind of issue I would suggest calling our support at the number below so we can remote on and take a look.

Cadence (Cay) Denning
Support Engineer
Rose Point Navigation Systems