Does anyone know if you can use the typical street navigation GPS systems (ie: Garmin, Tom Tom, etc) for fishing purposes?

Do they have features where you can type in the coordinates and it will lead you right to that area. And also, I would like to have the ability to save an area as well. And/or do they make fishing map cards for those units as well.

I have some that I am going to try to buy in an auction and just looking for another way to save money.