You will get 3 opinions on the water scoop.... maybe more if you throw in the SS tip RTGs. One of three would be Stealth 720, T-Rex, or one of the StavRs. Those are the hot tickets right now. Chucks Stealth has a lifetime warranty and keeps changing for the better. You choice may depend on the conditions you are digging in as well. In the shells you might like something with a point the round nose can roll on you. Also look at the back for a good foot rest.
Grave Digger Max has some great vids, but so does ole beach nut and a ton of others. Id watch as many as i can.... but there is no substituted for getting out there and swining the coil. The Xcal is a simple and forgiving machine. Lowest setting on disc, volume full, set the threshold so you can barely hear it, run in disc until you learn the machine, sensitivity will be the only tricky one. For the most part about the only knob you will adjust is the sensitivity once you set the threshold and start hunting. It will tell you if you are running to hot by the false signals. Most set it around 6 or 7. The first thing to learn is shallow bottle caps. After that dig everything but iron and those bottle caps. Targets initially will sound condensed.... but it wont be long until you get um down. Thats when the fun starts.
Dew