A native of Miami, Florida, David attended Indian River CC before transferring to Auburn, where he was an All-American and ranked as high as 6th in the world in the 100 backstroke. He earned his degree in business administration in 1981, and remained at Auburn as an assistant coach. In 1985 he became head coach of Dynamo Swim Club in Atlanta before going to the Las Vegas Gold Swim Team in Nevada in 1988. 

Marsh returned to Auburn as Head Coach in 1990, where his teams won seven men’s and five women’s NCAA Championships over the next 17 years. 

In 2007 Coach Marsh was offered the position of CEO and Director of SwimMAC Carolina. Here he created Team Elite which was comprised mostly of post graduate Olympic hopefuls. SwimMAC Carolina / Team Elite became one of the top programs in the country, winning several USA Club Excellence awards and Senior National Championships. After ten years David moved to UC San Diego in 2017, where he also relocated the Team Elite program. 

In 2022 he joined the University of California’s program, initially on an interim basis, before becoming their associate head coach. Here he was reunited with head coach Dave Durden, who had been his assistant coach at Auburn. Cal continued its winning ways, as they’ve won two NCAA Championships (six total under Durden). 

Marsh’s success is responsible for his being named to four Olympic coaching staffs (head women’s coach in 2016) with more than 60 Olympians from 20+ countries. He has also served as head coach of the LA Current of the International Swim League (ISL). 

David is a highly regarded speaker, having delivered addresses at both local and national events. He has also authored numerous articles for various publications and has provided commentary on a series of swimming technique videos. 

David and his wife Kristin, who swam at Cal, have one son (Aaron) and two daughters (Maddie and Alyssa).