You get one year of free unlimited updates from the date of purchase. After that, you need to renew the card. You can purchase the renewal on the Navionics website. As far as periodic updates, I usually update mine every couple of months, or whenever I go to a new lake I haven't been to before.
Edited by TinRangerJim (07/25/18 08:46 PM)
"Rip Some Lips"
Nevadan by birth, Texan by choice