Maybury won half of the six races in the series but counted all six results in the top three.
This year's championships was not contested by the defending champion Andrew Algeo in Juggerknot who has moved to the new J/99. Also not competing was Tim and Richard Goodbody in White Mischief due to crew issues.
Racing in northwesterly winds gusting to 20-knots, there were plenty of shifts on Dublin Bay to keep crews on their toes in the nine-boat fleet.
As it turned out, the overnight standings after three races here remained despite three further windward-leeward tests today. Second overall, and equally consistent, was Pat Kelly's Storm II from Howth Yacht Club on nine points.
Third, on 12 points, was Maybury's clubmate Andrew Craig, the Scottish Series champion sailing Chimaera.
Maybury who sailed to his fourth consecutive ICRA national title back in June on the same race track now adds the J109 national title in an impressive season for the RIYC team.
As part of the championships, Maurice O'Connell of North Sails Ireland was on the water coaching with video de-brief ashore after racing as below here in a sequence from race three on Saturday.