It's going to be tough without some sort of finder. Sure, you can tell somewhat what the bottom is like from where the shoreline enters the water but that only goes so far. If $ is an issue, I'd find some cheap fish finder on Craigslist. And remember, it's called a fishfinder but really you want to use it as a structure finder. I just bought a Lowrance Elite 4X from Craigs, brand new in the box for $100; there are deals out there if you are patient. You don't need anything fancy to get you going finding humps and ridges offshore. A Humminbird 597 Ci di is one of the best bangs for the buck and should be able to be bought for between $150 and $200.
Then get out there with some marker bouys, find some structure, drop a bouy and hit em with a t-rigged worm, jig, drop shot etc... Then in the fall you hit the same places with a blade.