You can start at the bank and fish out deeper and figure out where the bite is best. But when a storm with 5 ft rolllers comes up you can't even guess where you are without a good GPS. Not having a clue is probably the worst feeling I have ever had as a father, being lost in a storm on a lake. Don't chance it. Your GPS when turned on, will show you where you started, and allow you to get back. zoom might be the most important setting on a handheld.