Gamat Bay is one of the tourist attractions in Nusa Penida, but it cannot be accessed as easily as Crystal Bay.
By land you can reach the top of the hill overlooking the beach.
And then go down following a fairly easy path.
Gamat Bay is also much more remote.
Which means you probably won't see anyone down there.
Except for snorkeling or diving boats in the morning.
If you want to snorkel from Gamat Bay beach, you can bring your own equipment or rent it on the street, before parking your motorbike.
And don't forget the fins because the current can be very strong, as often happens on the island of Nusa Penida.