The XS is one of the favorites for many and with the 8 inch Coin-search coil you have a great combo, the only thing missing is the Sun Ray 180 meter, that is if this is the one that's been advertised on the classified and was hoping some one would buy it as I was very tempted myself and have too many detectors now.
Now the coin-search coil when I used it was in wet grass with no problems, but was told not to dunk it in the water as water will get in, think it mostly would get in where the coil cable goes in unless there was a crack in the coil. The one guy I used to talk to in our club said he put some silicon around where the cable goes into the coil itself and didn't have a problem on the beach, but never dunk it either.
If you never used a Sovereign before you will see it is different and remember to have patience as all will say that learn this detector they hate it at first, but after they learned it they love it and have the finds to prove it.
Good luck with it and if you have any question feel free to ask as we have several of us that has mastered this detector.
Rick