Seems to be a debate that comes up every year about should lines be in the cave or should lines be in OW. As a cave diver I have come to accept that many of the common practices that we have,have reduced accidents among the curious seeker and OW divers,and some of these practices can inconvenience me,but a small price to pay to keep my sport off the radar screen of government officials.
The debate is having line in open water is an enticement,but gives the person a fighting chance to find their way out. Line back in the cave zone does take away some of the enticement,but if someone truely is lost, they don't have a way to find their way out. I agree with having line OW in places where no open water divers are allowed,for example P1. But having line in OW in nonmonitored locations has proven to have its downfall with some incidents/accidents. For example,someone gets back into the cave having followed line from OW,they silt up the place,and they have the line,but they follow it wrong way,even blowing by navigation arrowns which they don't understand.