I have never used any type of metal detector in my life. I do have a heavy tec back ground and often find myself on the bleeding edge with new toys. I have several things like quadcopters and ROVs which I swear are using beta software on their products. My interest in a metal detector stems from my owning a big catamaran I often cruise on for months at a time (as long as it is not hurricane season). Location is Florida, Florida Keys, Bahamas, Cuba during some administrations, and down island at times. Currently in Florida do the fun and games with COVID-19.
So the first must have for any metal detector is being water proof to say ten meters or so. I have a hookah on my boat and almost never go deeper than 33 feet (I do have certifications in Advanced Open Water, Search and Rescue, and Cave Diving) but the hookah allow almost unlimited diving with out needing to get SCUBA tanks refilled. There are also lots of cool crystal clear freshwater springs I frequent and would like to do searches there. Not to mention some old settlements and Indian mounds. The ability to search in salt water is very important but I would also like to search in fresh water and on dirt as well.
Bottom line is talk me out of getting a Fisher CZ-21 and advise about getting the 8in or 10in coil. I tend to jump in with both feet and understand that out of the box I will be taking it to local beaches to hunt for bottle tops and such to start and dealing with a learning curve that will take time to master.
I am not wedded to the CZ-21 and open to other suggestions. Feel free to correct any errors you think I have made.
So the first must have for any metal detector is being water proof to say ten meters or so. I have a hookah on my boat and almost never go deeper than 33 feet (I do have certifications in Advanced Open Water, Search and Rescue, and Cave Diving) but the hookah allow almost unlimited diving with out needing to get SCUBA tanks refilled. There are also lots of cool crystal clear freshwater springs I frequent and would like to do searches there. Not to mention some old settlements and Indian mounds. The ability to search in salt water is very important but I would also like to search in fresh water and on dirt as well.
Bottom line is talk me out of getting a Fisher CZ-21 and advise about getting the 8in or 10in coil. I tend to jump in with both feet and understand that out of the box I will be taking it to local beaches to hunt for bottle tops and such to start and dealing with a learning curve that will take time to master.
I am not wedded to the CZ-21 and open to other suggestions. Feel free to correct any errors you think I have made.
back... from the Land of 10,000 Lakes - Minnesota! 
Happy hunting! 
