I’ve used and contributed to OSM for many years (10?). I have an old Garmin Etrex Legend HCX of similar vintage, and for all this time I have built maps for it using the Geofabrik extracts, splitter and mkgmap. I don’t do anything clever, just build with default styles etc.
Initially the maps on the GPS showed areas of water (lakes, sea etc) coloured light blue, but a while ago (18 months?) this stopped happening and lately they have just appeared as white. I can’t pin down very closely which version of mkgmap might have done this.
It’s been a minor annoyance - the rest of the map has seemed OK. My old PC used to take over half an hour to build a gmapsupp.img file just for England, so experimenting was a bit painful. But now it has died and I have a much faster new one that will do the job in 5 mins, so I thought I might try to fix this.
I expect it’s a style problem somewhere, some modified tag or element mapping is now incompatible with my old device. I’ve been looking through the style files and trying a few things, but had no luck. Any suggestions where I should look?