amphibious vehicle

From what I've read, the first oceans condensed from vapors of volcanic origin. They were not saline, the water cycle had not yet rinsed salts into them from terrestrial watersheds, so they made perfect germination pools for amphibians, those most tender creatures, no longer found in the now heavily salted seas, only in fresh water. But it seems to me all water is fresh, no manners at all. It just touches you wherever it wants, even from the inside.