Colour of water areas

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?

Do you use precompiled sea? I think some versions of this file could cause problems, but rather for sea than lakes.


Historically, no I have never used precompiled sea. (Such advanced tricks didn’t exist when I started, and I never got around to using them.) I tried it once just a day or so ago to see if it helped, but it seemed to make no difference.

Solved. Somehow - finger trouble - the “marine colours” setting on the device display confg screen had become set to “on”.

Thinking about TYP files, and browsing through the area type IDs list on the OSM wiki gave me the clue I needed.