I have been shooting the G16 in a Fantsea housing with a Subsea +10 and a sea and sea ys-d1. I've been loving it. I know you have to get closer than with some DSLR's etc.
I upgraded about 1 year ago from a Sealife dc1400 and began shooting manual and raw on the g16, for Christmas i received the Subsea+10 along with a L&M sola 800. I finally got my entire setup in the water for a good test last month in Dominica and I am very pleased with the results.
There are a lot of photos here the good and the not so good but you can get an idea