Sony has announced the Xperia M4 Aqua at Mobile World Congress in Barcelona, introducing an update to its mid-range smartphone portfolio rather than a new flagship.

Just because it isn't flagship territory however, doesn't mean the Sony Xperia M4 Aqua can't pull it out of the bag. With a design almost identical to the Xperia Z3, the Xperia M4 Aqua is not only waterproof, but light, slim and cheap at €299.

It measures 145.5 x 72.6 x 7.3mm, hits the scales at 136g and the M4 Aqua does away with the flap covering the Micro-USB charging port for a more seamless finish. There is a 5-inch display on board, offering a 1280 x 720 resolution that delivers a pixel density of 294ppi and the Xperia M4 Aqua has an octa-core Qualcomm Snapdragon 615 processor running the show with integrated 4G LTE.

READ: Sony Xperia M4 Aqua hands-on

On the rear, there is a 13-megapixel camera with f/2.0 aperture and ISO 3200 sensitivity, while the front offers a 5-megapixel snapper with an 88-degree field of view to get everyone in the shot.

The Xperia M4 Aqua will come with the full suite of the camera software features found on the Xperia Z3, including Superior Auto and Sound Photo, plus there will also be a Portrait Retouch function for adding finishing refinements to selfies.

In terms of main software, Sony will launch this device with Android 5.0 Lollipop but it won't come with the company's Remote Play function that allows PlayStation 4 users to play games remotely on their smartphone. The Xperia M4 Aqua will come with the new look Xperia Lounge Silver however, which is a service that delivers apps, software updates, entertainment, offers and tips.

There is a 2400mAh battery on board, which Sony claims will deliver two days of juice and you'll find 8GB of internal memory that is expandable via microSD.

Sony's Xperia M4 Aqua has been introduced to "reboot" the mid-range and bring battery life, waterproofing and decent cameras to everyone. It comes in black, white, coral and silver colour options, with a price tag of around €299.

UK pricing and availability has yet to be detailed but Sony has said the Xperia M4 Aqua will arrive in Spring 2015, so expect to see it around April.