Rio Bay is on the eastern side of The Lake. The little town of Rio is off the bay, and Long Island is across the entrance to Rio Bay.
Now they could see Rio Bay and the steamer pier. They were slipping slowly through a fleet of yachts at their moorings. Motor boats were moving about with cargoes of visitors .... Rio on this summer day was a busy place. A steamship hooted, left the pier, and steamed slowly out of the Bay (SA8).
The steamer was coming out of the Rio channel betweeen Long Island and the mainland (SD1)
In Rio Bay the ice round the steamer pier and out beyond Long Island was black with skaters (WH10).
Going down into Rio they saw the sparkling waters of the bay, with its landing-stages and its anchored yachts (PP1).
Rio Bay with its crowd of rowing boats, its moored yachts, its boat landings, the steamer pier, and, beyond it, the big sheds of the boatbuilders ..... and two big buoys that marked the rocks that the steamers had to avoid. Dorothea thinks back to Rio Bay all ice and thick with skating Eskimos (on the winter day they found the North Pole) (PM14).
Dorothea wants to go to Rio, But one glance towards the crowded bay, with its trippers windmilling around in rowing boats, and a big steamer just leaving the pier, decided Dick. Once in there was enough for one day (PM16).