App Doesn't load

I'm connected to my boat with Wi-Fi but when I try to load the app, I just get the blue screen with the boat and the words "Active Captain"

It's not the boat as I have had this problem with 2 boats.  Seems like it needs a cell signal but why?  I already update the app software ready for down load and all that should remain is to connect with the boat and load from my phone.  Didn't work on the dock, but worked when I trailered one boat back to the house.

Go figure.