@bdevis Have you provided your inputs for our software feature survey? There’s your chance to have a say with what the community wants for software features and one of the items is for iOS compatibility.
From looking around at the rest of the internet I have’t seen any good reviews of an iPad pro working well with water. Example here.
I think the Galaxy Tab Active2 or similar will be an interesting choice when we have mobile compatibility.
If you are really concerned with water ingress, then I think you are looking at a rugged/semi-rugged laptop or tablet solution. There are many manufacturers out there such as Panasonic, Dell, Getac, etc. I think Dell is the only you can buy off-the-shelf right now and customize how you want it.