Thanks for the comments guys;Sandta, I took my time and gridded with a reasonable overlap on most runs so I'm pretty sure most of the targets were picked up, having said that though I've probably missed a few, nobody gets all of the targets in an area. Due to the wind and surf noise some of the real deep targets were a bit hard to hear even with the booster volume turned up so it may be worth another look a bit later, it will depend on how the silvers clean up,one of the florins is pretty well worn back to a flat disc.
Cheers, SinHof.