There has been a lot of conversation about this option, but it seems very few people are actually doing it.
The biggest hurdle seems to be finding a monitor or PC that are durable enough, have good visibility in direct sunlight, and don't cost more than another Humminbird unit would cost. The Toughbook seems to work good for this, but is an expensive notebook computer.
I am planning to look into this further myself once I get my 1197 up and operating this spring.
Any TV or monitor that has RCA jack inputs for video can be used. Wayne has posted pictures of his unit connected to a flat panel TV.
(You do need to have the Humminbird cable part # VC-1)
Please keep us informed if you find a good monitor solution.