It was a drift dive--flags are essential.
There was nearly no current. Our skipper guessed it was going north, if at all. When we reached the bottom, I hovered long enough to see that it was going south, and we set out at an extremely slow pace in that direction, staying at the edge of the reef. I later learned that two of the other groups from our boat had done the same, but one group had accepted the skipper's guess and gone north. That gave us a bigger spread than you would expect.
Not long into the dive, we were passed by a hunter heading north. He appeared to be on a mission, swimming pretty hard with his spear gun. He was not pulling a flag. I would guess that this was the diver from the other boat who popped up in the middle of our spread. I would further guess that he had hooked his dive flag off and gone hunting. This would put him in violation of the flag law, since he was now nowhere near it. It would also explain why they were not surprised to find resistance when they tried to pull up the flag later on. They expected a connection they could break off with a enough effort.
There was nearly no current. Our skipper guessed it was going north, if at all. When we reached the bottom, I hovered long enough to see that it was going south, and we set out at an extremely slow pace in that direction, staying at the edge of the reef. I later learned that two of the other groups from our boat had done the same, but one group had accepted the skipper's guess and gone north. That gave us a bigger spread than you would expect.
Not long into the dive, we were passed by a hunter heading north. He appeared to be on a mission, swimming pretty hard with his spear gun. He was not pulling a flag. I would guess that this was the diver from the other boat who popped up in the middle of our spread. I would further guess that he had hooked his dive flag off and gone hunting. This would put him in violation of the flag law, since he was now nowhere near it. It would also explain why they were not surprised to find resistance when they tried to pull up the flag later on. They expected a connection they could break off with a enough effort.