If you are silly enough to go diving into the ocean with your Olympus OM-D E-M5 Mk II camera - and we have encountered a number of you who are...- we can at least help you protect the camera against the harsh element.
You will still be subject to all the dangers of the deep - sharks, giant octopi, sea serpents, mermaids, etc. but this housing by Olympus is the protection the camera needs. You'll be far more familiar with what it is that you want to do...besides surface eventually...so I cannot tell you how to take underwater photos. What I can point out is the wide range of controls that the housing allows access to under the water.
As you may possibly be gloved, he controls are oversize. As you cannot read most of the inscriptions on the camera, the position and the size of the controls is adjusted to allow you to discriminate amongst the buttons by touch.
Please be aware that anything that goes underwater reliably and comes up again is going to be costly - whether it is made in South Australia or not...The price for the housing is almost that of the camera. But it works a treat.