if it is a cooper river dive, you can stay shallow 16-18 feet and have a vis anywhere from 6 to 20 feet. go below 20 and you lose the vis quickly.screw drivers or picks are a must, you really need to be confident in your skills for the cooper river. i do not suggest anyone go out there by themselves unless they really know the rivers personality. she can get "swift". diving the incoming tide is usually better.always try to come up next to the boat, there are alot of uneducated boaters out there that do not know the laws of the displayed dive flag or bouy.there was a diver killed a few years ago on the cooper river by a drive over.as far as diving goes, the cooper river is extreme and not for the weak at heart. i used to be a firefighter, so, with that being said, i just love diving the cooper !!!