Second in the six-boat fleet is Tom Durcan and Clive O'Shea's T Bone two points behind O'Leary. Third is Gary Rhodes Heroes & Villains.
Over 70 boats are competing across 11 divisions in the premier South Coast Autumn series that has also attracted entries from Kinsale and Waterford Harbour.
In the IRC divisions, Conor Phelan's Ker 37 Jump Juice continues to lead in Class Zero IRC. Phelan is two points clear at the top of the in the six-boat fleet over club mate Denis Murphy's Grand Soleil 40 Nieulargo.
The RCYC leaders have established a good margin over a third-placed Kinsale entry, the Salona 45 Meridian skippered by Tom Roche.
In eight boat Class One IRC, Kinsale's Elan 333 Artful Dodger (Finbarr O'Regan) leads from Ronan & John Downing's Half-Tonner Miss Whiplash. Third is Paul & Deirdre Tingle's X-34 Alpaca.
There were great conditions again for racing in Cork Harbour in just under 10 knots of breeze.
Denis Byrne's Trapper T250 Cracker from Royal Cork Yacht Club has eeked out a three-point lead over the early Cove Sailing Club leader in eight boat class two IRC. The CSC Sonar, No Half Measures skippered by Ewan O'Keeffe is now second but still ahead of Waterford Harbour Sigma 33 visitor Flyover steered by David Marchant.
The Whitesail One division continues to be led by Derry Good's X 362 Sport Exhale. Likewise in the seven boat White Sail Two fleet where Kieran O Brian's MG335, Magnet stays on top.