'ample beach' is correct and usable in written English.
It is typically used to refer to a very large beach or a beach with a lot of room. For example, "We took a family vacation to an ample beach and spent the day swimming and relaxing in the sun."
Each room has a balcony looking out either over Canet's ample beach or the little courtyard garden.
Filming it with Kate Hudson on Australia's Gold Coast certainly provided ample beach time: "That place has a lot of bite to it – in the air, and in the water, and on land.
Ever since Hamilton introduced Tobias to the world in June, she and her new family have had ample beach time -- enough to ensure the little grom's future as a surfing legend.
And if you book your travel with intentions of staying a few days before or after the fest, you can have ample relaxed beach time sprinkled in the mix.
The country of Panama is blessed with beautiful islands, ample coastline beaches, mountain retreats, and colonial towns.
While I had no complaints about the white sand beaches, ample hammocks and tropical cocktails, I was turned off by the overdeveloped oceanfront and omnipresent beachside hawkers.
Its economy runs primarily off tourism thanks to its stunning beaches, ample water sports, and gorgeous hillsides.
This was coastal walking at its best – no complicated navigation, no hills to climb, just a pleasant route beside the beach with ample stops for swimming and eating.
Although most of the shoreline is public in California, state-owned beaches provide ample parking and well-maintained paths.
The nation's 14,000 miles of coastline offers ample choice of secluded beaches for water-borne migrants to slip in.
Islands seem to have it all: ample sunshine, white sand beaches, and species you can't find anywhere else on Earth.
