there is some new stuff for watermarks in 2013 that I have not tried yet (we are still on 2012).
in 2012, there is not a transparency setting for text - the work-around is to get it "behind" the drawing views and notes. you do this by putting it in a block in the sheet format, and setting it to a lightish color.
We also are on 2012. We placed a Block in the Drawing Format that is on its own layer called "Watermark". We changed it to a light gray and now you can hide or show the layer to turn the watermark on or off. I have also found that occassionally it is easier to add the watermark in Adobe PDF after making a PDF depending on what you are trying to do with the watermark. We use the watermark primarily to mark drawings that are preliminary when we share them with vendors.