What app is producing the GPX file? You can directly export a navionics route
into aquamaps on an iphone
. Same with the Garmin boating
just find your route in the route list and slide to the left and you will see "share", touch that then it will open up the destination screen
... scroll over till you see aquamap and then select it.
If you instead have the GPX in the "files" folder on the iPad
, then just find the GPX file and hold your finger on it, then select "share" from the pop-up menu and select aquamaps.