Ive been a land man for 33 yrs ,i was at the beach in Delaware this summer and found a navigational device from the 1700s with my cz70pro ,i was searching for gold and 1/2 cent pieces,after 3 days of hard hunting i did not find any ,after finding that piece,i found a new interest water hunting . i am a fisher guy with cz70pro and f75 and just wondering weather the cz21 8 or 10 or the excall 11 8 or 10 coil, is for me ,i plan on hunting beach, surf up to neck , I traded the navigational device to Dale at the musium in Fenwick for a king george 11 1/2 cent 1747 since i had the hots to find those 1/2 cent pieces ,so can anyone help me deside on the machine for me ?