Dave Marryman joined the CMS water polo staff as an assistant coach in 2016, and is entering his eighth year in 2023-24.
Merryman has also served as the co-head coach of the boys and girls water polo teams at Los Osos High School for 15 years from 2005-2019. He compiled a 585-248-1 record in that span, including 257-7 in league competitions. He earned 27 Baseline League Championships, after guiding the programs to their first ones in 2025, and won three CIF championships with both the boys and girls teams.
During his high school career, Merryman earned Coach of the Year honors six times from the CIF Southern Section, the Press-Enterprise and the Daily Bulletin.
Prior to starting at Los Osos, Merryman had collegiate experience as an assistant coach at Riverside Community College from 2001-24, helping his teams to four consecutive top-five finishes in the state. His teams finished second and third in the state championships in 2001 and 2003.
He also served as a national team manager and an Olympic Development Program (ODP) coach for USA Water Polo from 2011-14, taking the 2014 Cadet National Team on a trip to Serbia. He earned the 2013 ODO Pacific Coast Regionals Top Caoch Award.
Merryman earned an associate of arts degree in kinesiology, health and wellness and an associate of science degree in math and science from Riverside in 2004.