Maureen, I bought my Excalibur in June of last year, I have at least found 40 rings with it. In my case there are three things that have led to my success with the Exc. 1) finding a beach area that has been detected very little 2) buying probably one of the best beach / water machines 3) being willing to take time and learn how to use the machine.
My land Metal Detector is a Whites MXT , I first got my Excalibur II I cranked it up and went "OH NO". I went into shock at the "sounds", I started to dig and dig and bought CliveClynicks books all 4 of them and Tony Dana's sound CD.
I read the books and listened to the tapes and went into the local lake and immediately found 2 gold rings, I was and still am hooked. If you do a search on this site "Mexico" you should be able to see a picture of my lat es finds while in Mexico.
Read all of Surfdiggers messages, gulfhunter, oldbeecnut, gene Edwards emails, the excal is a challenge but well worth learning.
Maureen, the only thing I might suggest is buy the 8 in coil as it is easier to swing in the water and easier pin pointing, I bought the 10 and after swinging it for 6 hrs think an 8 inch might be better
Please keep us up to date with your finds from the beach regardless of what machine you get.
Gerry