And the Sea Kings return an experienced and talented core of athletes. Junior Shelby Buckley, who while attending Rosary High as a freshman won the CIF Division III state title, and senior Sarah Cummings, who was the team's No. 2 runner most of last season, will form a potent one-two punch.
Buckley and Cummings each bring something different to the team.
"We have flight of feet in Shelby Buckley," Sumner said.
"Sara always makes sure to cross the T's and dot the I's. She always goes beyond."
Junior Allison Damon and senior Nichole Slykhous also return from last season's team, which not only won the CIF State Division III crown, but defended its CIF Southern Section Division III title.
Sumner has deemed Damon "killer."
"She's the most emotional of the group," Sumner said. "She makes sure when we are supposed to be laughing we're laughing and when we're supposed to be crying we're crying."
In a group of runners with minimum 4.0 grade-point averages, Slykhous stands out.
"She's the scholar of the group," Sumner said. "She goes through all of the steps."
Sumner expects junior Allison Gushue and senior Hilary May to fill out the fifth and sixth spots, respectively.
Buckley and May were also part of the Sea Kings' distance medley relay that won a national championship with Buckley running the 1,200-meter portion and May running the 800.
Sophomore Laura Bilder, a varsity returner, will likely fill the seventh spot.
Freshmen Sarah Keddington and Kim Cordino, along with sophomore Reily O'Brien, who was the top runner on the freshman team last season, should also contribute, Sumner said.
"I would say we have a little bit of depth," said Sumner, who is confident in the mystique held by the CdM singlet.