Not to start a war here but personally most alternatives to apple products in my opinion are more useable. They are often times more open and offer more features hardware wise with rarely any On purpose locking of features with requirements to pay more cash to unlock um. And yes Apple does this.

If you where to get a smartphone for survival means I would go with a Android based phone with a Micro SD slot. The useability for this is endless with added apps such as the google one that reads the stars via camera and GPS. Im sure that would be massively usefull on the open water and such if it works there.