In the 1920s, the Port Jackson & Manly Steamship Company ran a seven-ship fleet comprising the Kuring-gai and six similar Sydney-built double-ended screw steamers: Binngarra (1905), Burra Bra (1908), Bellubera (1910), Balgowlah (1912), Barrenjoey (1913) and Baragoola (1922).

With construction commenced on a Sydney Harbour bridge crossing, and expectations that a rail link to Manly would be built in 10 years (but never eventuated), the company was seeking faster and larger vessels to compete.

[3][4][5] Quotations from Australian builders were considered too high, and proposals were sought from Britain for the design and construction of the vessels.

Dendy, then the general manager of the PJ & MS Co.[6][7] They were designed to provide a 17-knot service to compete with a proposed Manly and district train line that never eventuated.

[3] The colour scheme replaced the old black, white-striped hull which the Manly fleet had carried since Phantom.

Navigation bridges and wheelhouses were located at the fore and aft ends of the sun deck.

Padded reversible seats were also introduced in contrast to the older ferries' fixed wooden benches.

Passengers could order breakfast, lunch, dinner or supper which was served with silver cutlery embossed with the company's insignia.

[8] Each ship required thirteen crew and could carry up to 1,587 passengers, a capacity that was reduced to 1,199 in rough weather.

[4] They were the second-last steam powered ferries built for the PJ & MS Co, possessing inverted direct-acting four-cylinder triple-expansion fully reversible steam engines manufactured by David and William Henderson and Co, of Glasgow, producing 3,200 horsepower.

The vessels had steam assisted steering, electric lighting, chemical fire extinguishing and Mechams engine room telegraphs.

[2] A storm in the Bay of Biscay ripped off part of Dee Why's sponson and water was taken with pumps blocked from builder's debris.

At one point, Dee Why broke a main steampipe and she drifted for 10 hours until taken under tow by a tramp steamer.

Ultimately, both boats stayed in Aden for two months during which time most of the crew had to be forced on board.

Rough weather was experience between Aden and Colombo and the ships continued past Java stopping at Surabaya on its north-east coast.

Seventy miles from Sydney, Dee Why ran into a southerly gale and sheltered for 37 hours at Cape Hawke.

[4] When the two sisters were run free (ie, continuously and not to a time-table) to move Anniversary Day crowds in 1936, they completed trips in 22 minutes, which required an average 18 knots (the vessels' theoretical maximum).

[3] They proved most popular with the traveling public and attracted significant extra patronage for the company.

They were not only bigger and faster than preceding ferries including—Binngarra, Burra Bra, Baragoola and Barrenjoey—but also better sea boats and better appointed.

Company chairman, Hunter McPherson, described them as "splendid carriers, fast, excellent sea boats, economical to run, wonderfully easy to handle under conditions".

[6] The two ferries lead largely safe and quiet careers on the harbour; however, they had their fair share of incidents: In 1960, PJ & MS Co financial circumstances had declined, and the Curl Curl was decommissioned on 25 October 1960 following Baragoola's recommissioning after being converted to diesel.

[4] Dee Why was towed out of the harbour on 25 August 1976, by the tugs Rozelle and Fern Bay, to a point two-and-a-half nautical miles offshore and scuttled off Long Reef.

Her remains lie in water 51 metres deep at 33°41′S 151°20′E / 33.683°S 151.333°E / -33.683; 151.333, and forming an artificial fishing reef.