You probably don't want to spend a bunch of money. But let me tell you, a couple bucks spent now will save you alot of money and maybe even your life in the long run. There are any number of dash mounted, portable, GPS depth finders on the market now. The very nice ones have the nav aids and depth charts included. If you can do it I would invest in one of those. I have one in my 26' that is transportable to my duckboat and even my car.
OR the economy route is a portable battery powered depth /fish finder and a handheld GPS. Use your GPS to tell you where you are and the depth finder to stay off the sand bars. With the many storms we have had shoals, sand bars, trees and crabpot tangles shifted about and you don't want to become fouled. Let a fog set in and you will waste your draw on finding the blind or getting rescued.
Life is like a box of chocolates,
dark, gooey and someone is always sticking their finger up the back to see what's really inside.