[ful-rac]

Your on the right track, no amount of youtube or pictures will replace OTW experience. there are many variations of fishfinders, transducers...or even how they are mounted, they all will make a difference on how they read. Try to meter known objects, like what you are doing...kelp, dolphins, rocks, sand, bait...and note what they look like. Next time you hook a fish try to get it into your sonar cone and note what it looks like. After time you'll get a sense of what things look like and what they are or likely to be. Hopefully this helps.