Coaches & Directors

We are here to support your needs. If your questions are related to workouts, meets, events, goal setting, and other Swimming/Water Polo related issues, please do not hesitate to contact  a coach. For administrative inquires such as dues, safety, or policy issues, please contact a member of the Board.

Coaching Staff

Mark Johnson

Head Coach


Coach Mark Johnson has been with the Cerritos Aquatic Club since 1975.  Mark was a Junior Olympic and C.I.F. Champion, Yale Swimming and Water Polo Captain, and an All-American Water Polo player.  He has taught swimming for 45 years and coached Varsity Swimming and Water Polo at Cerritos HS and Whitney HS for 35 years.  He is still passionate about bodysurfing, traveling to Hawaii, Australia, Mexico, and Brazilfor surf trips and competitions.  He is passionate about encouraging all swimmers to stay in shape for life and to help others learn to swim.

Paul McManus

Head Water Polo Coach: 14 & Under


Coach Paul McManus has been with the Cerritos Aquatic Club since 1979.  Paul was a standout High School and College Water Polo player and swimmer, and has been the Varsity Water Polo Coach and Varsity Girls Swim Coach at Whitney High School for the last 25 years.  Paul is our club's Head Water Polo Coach and has lead our teams to countless wins over the years, including our Junior Olympic age group teams to top finishes in the Platinum and Gold divisions of the annual National Junior Olympics.  He has two grown children, one grandchild, and enjoys golf.

Sergio Cervantes

Assistant Coach - Senior Group


Coach Sergio has been a competitive swimming coach for over 30 years. His swimming and water polo experience started with Bell Gardens High School where he was the captain of his team. He went to swim and play water polo for East Los Angeles College and later became a member of the Mexico National water polo team.  Sergo has coached several All-American swimmers during his time as a swim coach.  Sergio is currently coaching at Kennedy High School in La Palma and is very excited to be coaching the senior group at Cerritos.

Nathan Umpornpuckdi

Assistant Coach - Junior Olympic Group


Coach Nathan started swimming with Cerritos Aquatic Club in 2008. He was awarded Most Valuable Swimmer from Walker Jr. High. He swam 4 years on Varsity at Kennedy High School. During those 4 years, he was awarded MVP and Coach's Award and also helped his school win 3 Empire League Championships in a row. Nathan was a CIF Finalist from 2010-2012 and swam at CIF Masters in 2011. Nathan was also a Junior Olympic Swimmer, he swam 100/200 FL, 100/200 BR, and 200/400 I.M. In 2012 he swam at the CA/NV Winter Sectional Champs. He also competed in the pier swim and open water swim for the past 6 years. He remains active and participates in 5K and triathalons throughout the year.

  • Southern California All-Stars Coach 2016, 2017 & 2018
    • Athletes from his group participated in the All-Star festival: 2016-2018
  • NACC (North American Challenge Cup) 2017 Assistant Coach
  • Southern California Metro Committee 2016 Coach of the Year
  • Whitney High School Swim Coach 2017 & 2018
  • Rough water Champions - (athletes from this group)
    • Open Water @ Seal Beach: 2015-2017
    • Western Zone Champs: 2016-2017
    • Junior Olympic Open Water: 2016-2017

Don Conner

Assistant Coach - Varsity Group


Coach Don was born in Santa Monica, CA and has lived in Southern California all his life. Growing up in Costa Mesa and Anaheim, he swam and played water polo for Estancia High School for two years and then transferred to Loara High School for his last two years. While in college he coached water polo briefly at Loara and a few years later he began coaching at Western High School in Anaheim. Over the last twenty years he has coached boys and girls water polo and all levels of swimming. Coach Don is the head coach of the girls varsity team during his time at Western he has helped lead the Pioneers to multiple league championships.  In his free time Coach Don enjoys spending time with his wife and two dogs Cash and Bentley, he also enjoys photography, golf and traveling. 

Joseph Owens

Assistant Coach - Bronze Group


Coach Joseph started coaching for Cerritos aquatics March 2015. Along with coaching, he is a swim instructor for the city of cypress in the summer.  Joseph has been competitively playing water polo for over 6 years and swimming for over 9 years.  He is a full time college student and Is majoring in Law and Criminal Justice.  His long term goal is to achieve a masters in Criminal justice and become a detective. Joseph loves playing any type of sport and loves to travel in his off time. 

Ailien Nguyenly

Assistant Coach, Bronze Group


Board of Directors

Jerry A Dornoff



Niketa Mehta



Patricia Neri



Christine Oliveira



Ruben Polanco



Edward Lee



Janis Fok