Defending Beneteau 31.7 champion Chris Johnston in Propsect leads into Sunday's final races but only has a one point margin over Royal St. George challenger Michael Blaney in After You Too...
The one-design championships are also being raced for under ECHO handicap and incorporated into this weekend's Unio ICRA National Championships at the Royal Irish Yacht Club in Dun Laoghaire Harbour for the first time.
For a second day, light but stable easterly winds have allowed a full programme of races to be staged on Dublin Bay, with two Sunday's final two races -again in forecast light winds – to be the championship deciders.
The National Yacht Club's Johnston counts 1 (3) 3 2 1 after five races sailed to be on seven points, just one ahead of Blaney, who counts (3) 2 1 3 2.
Lying third is Michael Bryson's Bluefin Two on 11.
Nick Holman's Extreme Reality leads on ECHO handicap in the ten boat fleet.