Hiya
One good thing about having a set group of divers that you dive with is that you soon learn each divers style. We HAVE to dive in close proximity to each other, due to the schooling nature of the fish we hunt as well as the shark threat. With up to 4 divers in the water, drifting in the currents, we easily and safely spear together. We normally will spilt up into two pairs. With each diver alternating with their partner. One up one down. I normally check when i surface where the other two are and try to stay relatively close........yet not TOO close.
Be VERY careful of where you point your gun!! In clean water, diving with a few other spearo's is easy. How-ever, this changes in dirty water. Always make sure you know where the other divers are before you dive. DON'T EVER shoot a fish if your dive buddy is in front of you!!! No fish is worth the risk of injuring your buddy!!!
Other than that, normal common sense will see you through most situations!!!
Regards
miles