Yes it can, as long as that water is fresh water, if you mean salt water and land then unfortunately your going to need two machines (as the only machine I can think of good for both is the ctx 3030 and that's $2500).
It also depends on your soil type, id say to go look at some metal detecting videos in your area on youtube and see what they are using and their success rate with them, some soils can prefer some detectors.
When you draw up a short list then check peoples views of those particular machines, the good and bad side so you get a good overall idea of what goes right and what can possibly go wrong.
Its easy to recommend you the at pro, I own one afterall but just because a machine is good for me doesn't mean its going to fit you.
I can say I chose mine as its good with this soil, I lost the worry about it falling tinto a puddle and I can lake hunt if I want, its light (2.9lbs with the 5x8 coil) and powerful for its price range.
Its pinpointer is spot on ive found and the headphones although sweat inducing offer good sound and are comfortable around the ears.
It is also good to teach yourself on with its STD mode for first timers on park settings but its pro settings show you the real machine (depth, sounds, discrimination).
I'd recommend when you do find the type of machine you want then to look around here for some second hand ones because so many people start and find its not for them (potentially detecting for 5 hours and getting less then a dollar in clad and filling their pouch full of trash three times over).
If you have the funds id also recommend a garrett propointer as its retrieves the find from the hole/flap you'll dig a lot sooner and you always check the hole again after each find incase its a pocket spill, horde, or something was masking something else much better.
The other thing is the hand digger, most seem to be avid fans of the lesche hand digger, me included, its comfortable, cuts nice neat holes (you should almost never need to cut a flap more then 4" wide for a 6" or under find).
The flat bar infront of your hand also gives you something to push against for the harder cuts and I have yet to see someone who bent one, unless they were using it like a pry bar on a boulder.
The overall cost with an at pro, lesche and gpp would total you to about $700 for new, so think on that if you can find a setup second hand (you can also ask around to see if the price your offered for a second hand unit is good (there is a first generation at pro people arnt so keen on as it needs an upgrade and doesn't have the cam locks)
The only other thing id say is that its sometimes better to go for a more basic cheaper machine till you understand if you want to stick with this hobby, it can get mucky, tiring, cold, miserable when you spend hours and get skunked for any type of finds.
Oh BTW, make sure you have the places to hunt, check locally not just for locations but if your even allowed to hunt there, some don't realize that theres laws around them banning most hunting places and if you have an acre garden you can only look there so many times till your not going to find anything else.
Some on here spent their entire winters locating places to ge them through the next year, collecting locations and permissions and then going back to places that tend to replenish every so often like totlots, parks, school yards, public places where people gather like fairgrounds on the town center.
The more you prepare the less likely you are to get the wrong machine, get the wrong accessories, get the wrong places to hunt and have too high expectations, all of which cause the drop out rate here (and can cause there to be some nice deals on almost never used machines)
OK..hope this all helps
