STLKayak wrote:
I am not going to get into the legality of more than one person on your PA12. I have done it quite a few times on my PA14. I use the chair from my BPS Ascend kayak behind my Vantage seat. I also have a seat from a Jackson Cuda that works well. I like the way the Bass Pro Shop seat distributes the weight better than the Jackson. I have seen others using different low-boy beach chairs.
My only issue with you using the Yeti is that she is going to be sitting pretty high in your kayak. Her behind is going to be about the level of your shoulders, and that is going to affect your center of gravity. In my opinion, the lower the passenger is to the deck, the more stable you are going to be. Again, that is why I like the BSP chair, it is low, but fairly comfortable, for a decent price. (Around $100).
Here is a picture of what I use... I just strap it in with NiteIze gear ties.

First off thankyou to everyone for the reply, I was not aware that there would be legal issues with having an extra person on the kayak.
With your seat,what is the weight of your passenger and yourself?Does it affect stability too much? And what water conditions can you fish it in, your picture is pretty much what I was considering. the pro angler has so much space in the back im not sure why it cant accommodate a passenger.