Sorry, I neglected to answer all your questions.
Since you are running an old version of Coastal Explorer, you’ll have to copy your .nob files to a cloud storage solution, like Apple’s iCloud Drive, then use the iPad app’s layer import feature. Click Layers > Import…, then Choose File. At this point, you’ll be able to browse your iCloud Drive, Google Drive, etc. to import the file to a Cloud Synchronized Layer, a feature your version of Coastal Explorer has no awareness of.
Also, to add more context about the free version of the app, it is intended as a planning tool, not a navigation system. If you had an updated version of Coastal Explorer, you would see these Cloud Synchronized layers on all your PC CE systems as well, as long as the app is signed into your psbangs account.
You can install the app on as many of your Apple mobile devices (iPad and iPhone) as you want.