Hello all,
I am currently working on creating a tutorial for the ThirdPerson Swimmable Water Tutorial which will provide step-by-step directions to get your volume working with some neat post-process effects as well. This tutorial will be coming soon, but no specific time frame can be provided at this time. I am working diligently to get this to the community because it seems to be a very common question for users.
Also I will be using a translucent water material in the Swimmable Water Tutorial, which I will also be posting a bit longer of a tutorial for in the near future. This might take a bit longer to get completed since the directions are a bit more involved and lengthy. In the meantime, thanks for all the great posts and let us know if you have any further questions! Look for the tutorial on the Wiki in the near future!