They may be doing maintenance for the app. May be some new features being added. Try again in a day or two.
Saw a message on another site that a person could not do an map card update over the weekend, so that must be what is going on.
I have Navionics Boating, Boating HD, and USA apps on 5 Android and 1 iOS device.
Edited by Wayne P. (06/15/16 06:48 PM)
Humminbird Helix 12 CHIRP SI, 1198c SI, 1198c SI, ONIX 10 SI NT, Helix 7 CHIRP SI GPS G2, 360, RC-1