I was a diver then. So, to answer my own question I pulled on the scuba gear, went overboard and suspended not far beneath the surface of a lake while several friends in a boat exercised their vocal cords. Yes indeed, I could hear them. In the years that followed, while fishing in clear, shallow water where I could see fish, I realized I was able to spook tailing redfish, bonefish and even cruising carp with a shout. Many of those fish veered off, but even the ones that hung around went through a change of attitude. Over the long haul, I've come to believe that such an awareness of something new in their environment makes fish more difficult, perhaps impossible, to catch. Some good anglers I know feel that even sharply stripping out line against a loud clicking pawl on a fly reel can spook bonefish in ultra-shallow water. All of which leads me to one point: Excited as you are at the sight of approaching fish, keep your yap shut.