Sony has just announced the Sony Xperia ZR, another high-end Android smartphone joining an already packed 2013 schedule. There's the Sony Xperia Z, Xperia SP and Xperia L already announced, so what does the Xperia ZR bring to the (pool) party?

The big sell here is waterproofing. As with the Sony Xperia Z, Sony has added water resistance, although with more vigour this time. So how do the Sony Xperia ZR and the Sony Xperia Z compare? What's the difference and where should you be spending your money?

We're taking a look at the rundown in specs to see which phone you should be taking into the shower. 

1. Water resistance

The Sony Xperia ZR comes with IP55 and IP58 compliance, making it proofed against water ingress at 1.5m for a duration of 30 mins. This means the Xperia ZR is protected against total immersion in water. The Sony Xperia Z, on the other hand has IPX5/7 grading, meaning it is only resistant to water. If you want to make a splash, take the ZR.

Sony even suggests that you can use the ZR to shoot underwater images and video. Try that with a Z and all you'll get is a broken device.

2. It's fatter, but shorter

We love the Xperia Z's design. The glass sandwich monolith is strikingly different. The Xperia ZR takes a more conventional design approach. It has a smaller footprint, measuring 131 x 67.4mm to the Xperia Z's 139 x 71mm, but the ZR is fatter, at 10.4mm thick compared to the 7.9mm of the Z. That might not make a difference in your pocket though, and neither will the weight difference at 140g (ZR) to 146g (Z).

3. Display

The different in size comes down mainly to the display. The Sony Xperia ZR has a 4.55-inch display, whereas the Xperia Z gives you 5 inches. Both are large, but the real difference is in resolution. The ZR has 1280 x 720, the Z a sharp 1920 x 1080 - one of the first Full HD handsets to hit the market. The downside of the Xperia Z is that the blacks aren't quite as deep as we'd like and the viewing angles aren't brilliant, so the ZR could still be in the fight.

4. Shoot yourself

The Sony Xperia ZR offers only a VGA front-facing camera. It's likely to be 0.3-megapixels, whereas the Sony Xperia Z boasts a 2-megapixel front camera. That means the latter device will give you better quality self-portraits and better quality video calls, albeit not underwater.

5. Memory

The Sony Xperia ZR is listed as offering only 8GB of internal memory, whereas the Xperia Z will give you 16GB. That's not a huge deal, as both offer expansion via microSD.

So which to choose?

There's not too much to choose between the two. Certainly, on a rundown of the key specs, it's the size and resolution of the display that is the real difference between these handsets. We'd expect the software experience and the camera performance to be very much the same. The Z is the flagship model, it pips the ZR in a few areas, but the new handset will be the better choice for those looking to dive into the pool.

Of course, we'll bring you more on the Sony Xperia ZR once we get our hands on it for a full review. In the meantime, why not read our Sony Xperia Z review?