HI there!!
So im ultra newbie , did read some stuff but still very green.

I have recently purchased a handheld gps , the Garmin GPSMAP® 79s. Living in South of Portugal , fishing and spearfishing near the shore as been my thing.

From what i have understood, its possible to get a chart, put in sdcard and use in this gps . IF not from a shop, where to get charts ? I see some users requesting charts in a topic... if someone shares a chart, is it possible to put in the sd card and export to the gps unit?

I also saw that newer units need to be patched to use unlocked charts, one thing i didnt understand is , whats does unlocked chart mean?

Thanks to everyone in advance! Sorry for my ingenuity.