Just so your aware, that Ace 250 will not work in the wet sand very well at all, it can be used there but you will need to turn the sensitivity way down to get it stable, turning the sensitivity down will also be turning down the depth of your detector. Saltwater has lots of minerals in it, your detector will basically think it sees metal everywhere and will be constantly falsing unless you turn it down till it is stable, and there goes your depth............
Water detecting, especially salt water is a very specialized part of metal detecting. While almost any detector can be used on land, only a few can be used in saltwater, due to the salt minerals. You need a good multifreq VLF detector or a PI (pulse induction) detector to realy work the saltwater beaches....
The Garrett Ace 150, 250, 350 can all be use in the dry sand at saltwater beaches, but once you go below the high tide line your going to start to have major issues with it. If you use it at the beach, protect it with a bag over the controls, the salt mist in the air will get inside and it will eventually give you problems....
On the scoop, for 80$ you can get a good sand scoop, but $80 is not going to get you a very good scoop that will hold up to digging in the wet sand, you put a lot of stress on your scoop when digging in the wet sand. My first scoop was an $80 scoop, I was told to buy a good scoop, but I thought "$80 is a lot of money, it has to be a good scoop". I broke it within 30 days of buying it, snapped the handle off while digging in the wetsand......
My suggestion is to try to save up a little more money and keep your eye on our classified section, there are good used water detectors sold there by members you can trust. Your much better off buying a good used water detector, than a new Ace 250 for the salt beaches..... Ace 250 is great on land for beginners, not so much so on salt beaches....
Something many new hunters dont know is your money once spent is not lost, the value is still there in your detector and scoop... I have bought used detectors and sold then couple years later for more than 75% of what I paid for them. my first good beach scoop for the wet sand in the water, the original Beach Brute made by RTG I bought used for $100 and sold for $75 2 years later when I upgraded to a new one, the Beach Brute II...