Yeah...that's not the problem. We were all straying away from typical GPS for Ag due to the trees overhead blocking satellite view on your original post. 

In a boat you're not under trees, same as most Ag fields. They work just fine in both those situations. 

But yes, a "normal" ag system like you're talking will record your speed, heading, date stamp, product(s), rate, target rate, swath width, elevation, etc etc etc every second. You can then print a map, look at it on a phone, computer, export to another program, or whatever. If you're saying one of these systems will work in your trees, then yes there are MANY options including the brands you've listed.