OK, this topic is about using a 12" display and all the ways it can be mounted. But it has neglected one display: the PC, which can have up to a 15" display and costs 1/4 of a 12" screen.
One can use a PC with a host of different navigation software, but only one is free and that is OpenCpn. Add a puck GPS and AIS input and you have a full featured program that will beat Naviopnics or Lowrance. Costs only $600 for the computer and a C-Dory cabin is an excellent place to use a computer, dry and even temp. A puck GPS is $50 and best of all the US charts are free. That's right, no cost for any US chart, provided from NOAA, the source of all US charting. And for those of you who cruise in Canada, for $20 you can get either the east or west coast of Canada. And that's a bargain. I don't need to point out that one can do a lot more with a PC: browse the internet, write a letter, even keep a log.
Also, one can move it to the best viewing place, on the dash or with a RAM mount in the V-berth entrance. You'll also need an inverter, a small one costs $25 if you don't already have one.
That"s $700 for a big screen display. Computer come in 10" to 15" sizes and I've even seen them up to 17".
Boris