It's quite funny how some rumours start.
Yesterday on a slow news day the Herald reported that Argyle's League One rivals Northampton were interested in signing Waters with no indication of Argyle being interested apart from a Northampton related story being printed in a Plymouth newspaper.
Soon after website The 72 repeats the same story and crucially adds that Argyle are also interested in Waters.
So either it's true and The 72 know something or they got muddled by the Herald article.
Edit. Pilgrim28 saw the same as me.