GPS Chart Plotter....Other options

I have a small Garmin 1490T that has lake maps on it and it is very handy, except the screen it so small it hard to use. I have been looking at chart plotters and the cost of them for something in a 7" screen or bigger. So I began thinking, when just buy a large GPS and load the maps on it.....doesn't it then become a chart plotter as you can also save your positions to it also. The Garmin 7200 has a large screen and has 12 channel GPS, color, and 1/3 the cost of a similar sized chart plotter. I am even reading about guys using their Ipads for the same thing as you can buy a usb gps fairly cheap. I think Navionics already has it for the Android phones. Shock and water are the issues but the Garmin 7200 should have the shock issue covered and I believe the water would be an easy work around. My current Garmin is fairly weather resistant and I sure a little prep work on a larger unit would make it that way also.

Read about programmers working on programs for these ipads that let you use an adapter to plug in your transducer to it and then you have a 10" color fish finder. They just need a way to power the transducer at a much higher power output than the 75w usb will do. The code is the easy part for guys that live and breath that stuff. I mean they have managed to write code the best codes out there can't stop......just thinking on this. Currently an Ipad would not take the abuse on a smaller boat.

Anyone done this already or have info about it.....Marine electronics are ridiculous in cost.