Awesome pics of Palau by my cousin David

[SeaHorse_Fanatic]

I think they are tethered because of the current and so they can concentrate on their underwater photography, rather than trying to stay in place. It would be very easy for them to become separated in a strong current if everyone is untethered and focused on getting that "perfect" shot, rather than where all the other divers are situated.

This is just a guess.

Anthony