yes, one time i lost sight of my buddy (my husband) and the vis was around 3 feet, very silty. but we had a lost buddy procedure, which involved doing a 360º turn looking up, down, and level and if you could not see your buddy after those three turns, then we would surface, find each other that way, swim to each other and then go back down. We stuck to that lost buddy procedure and sure enough, we both popped up, found each other, and went back down with no issues. Much better than continuing without them etc. Make a plan, and dive the plan - that includes lost buddy procedures that should be agreed on before the dive.