I have an app on my phone called GPS essentials that works pretty well. It works on multiple satellites. Iv used it several times in the woods marking mushroom trees. All the trees will cause some loss of signal. I have only used it a couple times on the water just to see how well it works, Works great. I don;t use it for the fact I have gps on depth finder.
Crappie spawning and morels popping up at the same time. What was God thinking when he made that schedule. It's pure torture every spring deciding which to do.