Newport Harbor's undefeated boys water polo team is seeded first in a new-look Open Division for the CIF-SS playoffs.

The Sailors (27-0) top a 12-team Open Division that features four, three-team pools. The winners of each pool advance to the semifinals.

The 12-team field in the Open Division represents four more entries than the previous Open playoffs, which followed a bracket-style tournament.

The Open Division debuted in 2021. The previous eight-team size followed the Division 1 format that had shifted to eight teams in 2017.

The changes arrives in the first year that the section used the Massey power ratings to help construct the brackets.

The larger field in the Open grabbed most of the top teams in Orange County: defending champion and No. 2 seed JSerra (23-3), Corona del Mar (23-5), Mater Dei (17-8), Santa Margarita (16-8), Foothill (19-8) and San Clemente (20-7).

Westlake and Long Beach Wilson fell just outside the top-12 and claimed the top-two seeds in Division 1. San Juan Hills (19-7) is seeded fourth.

Division 1 begins on Thursday.

One of the top matches pits Laguna Beach against Los Alamitos.

Three other O.C. teams earned top seeds. Trabuco Hills (Division 3), Santa Ana (Division 4) and Garden Grove (Division 5) are seeded No. 1 in their respective divisions.

Divisions 1-6 feature bracket play. All the section finals will be played at Mt. SAC in Walnut on Nov. 16.

The Open Division semifinals are Nov. 9. The semifinals in the other divisions will be Nov. 12.