IOS 8.3 and external GPS We have an ipad air, which my partner uses to navigate whilst sailing with a programme called Navionics. 

The ipad version is WiFi only, which doesn't have an internal GPS, but that's not a problem because it connects to a separate GPS via Bluetooth. 

At least... It wasn't a problem until ios 8.3
Now, although the GPS connects fine,  Navionics can't use it to find its position. 

It's a known fault that many people have raised. Apple blame Navionics and vise versa and neither is suggesting a solution is immanent. 

Is there anything I've missed that might be a solution to let the Navionics app integrate with an external GPS?
This issue has plagued aircraft pilots for the last few months but there is a resolution on the horizon. Though there is no simple way to repair the connection for most programs, according to this blog: 
http://blog.foreflight.com/2015/06/02/ios-8-4-to-resolve-gps-accessory-compatibility-issue/
It should be fixed soon.