Having a quick look at the chartplotter on Molia.
![](https://molia.org/wp-content/uploads/2020/03/chartplotter.jpg)
It is a Raymarine RC435 with an external antenna. These date from around 2004, so it is probably an original installation.
![](https://molia.org/wp-content/uploads/2020/03/starboard-aft-rail-1.jpg)
You can see the antenna on the aft rail starboard side.
I am thinking of an upgrade, but need to do a lot of research!