There’re tons of battery cases out there for the iPhone, and a good selection of waterproof cases. But a battery case that’s waterproof? Just one: the new Mojo Refuel Aqua from iBattz.

The Refuel Aqua isn’t just mildly, get-caught-in-a-little-rain waterproof — it’s go-snorkeling-with-your-iPhone-for-hours waterproof; It’s rated at a mighty IPX8, the highest waterproof rating, and iBattz says it’ll seal out water at a depths of up to three meters.

You know how when the iPhone first came out and people were all complaining about how you couldn’t take out the battery? I know, right? The market swiftly moved in to solve the “problem” by supplying battery packs that could be added only when you needed them, and without rebooting the phone to swap them, and in whichever sizes you needed.

Now we have come full circle, as they say, with the Mojo Refuel for iPhone 5. It’s an external battery pack which — get this — has its own removable battery.