I'm brand new here, so please excuse any gaffes I may make, as to protocol.
I'm using an older, pre 'buyout' Fisher CZ-20, a machine I have used for 5 or 6 years, in the rivers of central Texas.
'Tubing' the rivers, here, is popular recreation, though, judging by my finds, damned expensive, for some of the 'tubers', as I find watches, jewelry, coin, and often, 'paper money', in bill clips, along the eddy pockets of the Guadalupe, and other rivers.
Just a thought for the use of that new 'Beach Hunter', if you have not considered such!
I 'paid for' the CZ-20, in just six weekends of use, with what I recovered, from the rivers, after sending back everything that could be 'ID'd' to a particular owner, like wallets, etc.
The question is obvious, so I will answer it, before it is asked; on the river, you will find 'Honey Holes', where everything seems to 'wash up', and when the machine tells me there is something there, I spend a lot of 'tactile time', feeling around the area, even after recovering the initial 'strike', and will usually find several more 'lost' items, with the search, by hand, in such places.
I log every 'find' on a gps, so as to be able to return to the location, eventually, and look again, at what the river has brought me.
Perhaps, some food for thought.