Yeah, more like a Caddy, one for the trash bag and one for the finds bag. Looks worse than an Italian beach with wasted drunk German tourist littering their curry ketchup packets and (pigpiss) beer caps.
You honestly have a much better chance of finding valuables up here in US tourist beaches. As a tourist, guides will remind you not to wear jewelry or bare minimum if you must and not to draw attention to yourself because there literally is an army of pick pockets, etc waiting to pounce on you. That in combination with most of the people on the beach consisting of the local lower economic level members of Brazilian society not wearing much if any jewelry would result in a day of finding bottle caps, garbage and some clad. Not to say that you wouldn't find some jewelry but like someone has already mentioned, there is a high probability that you may get mugged as there would be literally 100s of eyes on you wondering what you were doing with that machine. Also, as someone else mentioned, I believe the sewer system dumps sewage relatively within eyesight of the beach which I think was verified during the Rio Olympics where participants in various water events noted that they were competing in sewage filled water. Not a great motivator for water hunting if you ask me.
Those local treasure hunters likely would not take kindly to you showing up with a metal detector while they dig in random spots to find jewelry. With the price of wages in Brazil, no wonder they search the shorelines for gold. One or 2 decent gold items would be a months wage or more in Brazil.
Yup they search with a special rake and just randomly drag it up through the surf zone. Pretty interesting. I would be worried for my detectors safety.