Mark Kretzer enters his fifth season as the head coach for Saint Peter’s men’s and women’s swimming & diving teams in 2020-21.

Kretzer continued the program's upward trend during his fourth campaign in 2019-20, which include a 5-3 dual meet record on the men's side and three wins by the women, including a sweep of conference rival Manhattan. The Peacocks earned a collective 11 medals highlighted by a pair of top-three finishes on the men's side over the course of the 2020 Metro Atlantic Athletic Conference (MAAC) Swimming & Diving Championships, which saw the men place seventh and the women ninth by the end of the four-day competition. The program also placed 10 student-athletes on the 2020 MAAC Swimming All-Academic Team, while Justine Drake '23 was named the MAAC Women's Swimmer of the Week at one point during the season.

In Kretzer’s third season, the men’s swimming team posted its best season under his guidance with a perfect 3-0 MAAC record and an 8-1 overall record which included an 8-0 start to the season. The men’s team dominated in the pool, outscoring its eight opponents by 493 combined points, winning by an average of 61.6 points per meet. At MAACs, the Peacocks earned seven individual medals. Medalists included Oleksiy Polishchuk, Yann Le Gall, Arthur Bertrand, Andrew Galarza, and Guillem Perez. On the women's team, Rachel Valentine led the team at MAACs, scoring all of the team’s individual points and swimming as a leg on all five relay teams that scored team points. The swimming & diving teams also placed a school-best 12 student-athletes on the MAAC All-Academic teams during 2018-19.
 
During his second season at the helm of the swimming & diving programs, Kretzer led the men’s team to a perfect 3-0 MAAC record and a 9-2 overall record which included a 4-0 start to the season. He also guided the women’s program to its first win in two seasons with a wire-to-wire 103-82 victory over Stony Brook. At the MAAC Championships, Kretzer coached six individual medalists and his team broke three team records at the meet, while the men improved from the previous year with a sixth-place finish.
 
In 2016-17, Kretzer led the men's swimming and diving team to three victories, including a win on senior day against MAAC rival Monmouth. The men's team finished in seventh place at the MAAC tournament and Kretzer coach 12 student-athletes that made the MAAC All-Academic team.

Kretzer has served as the Team Suffolk Swim Club Elite/Jr. Elite Team Coach and the Half Hollow Hills Central School District Aquatics Director since 2010 and Aquatic All-Stars LLC Owner and Head Coach since 2009. He also most recently held the position of Head Girls Varsity Swimming Coach at Northport High School in Northport, NY. With Team Suffolk, he coached two 2016 Olympic Trial Qualifiers and numerous national championship qualifiers. As the Boy's Varsity Coach at Half Hollow Hills, he led the team to a New York State Team Championship in 2016. From 2010-2014 Kretzer coached the current Jamaican national record holder in five events.

Post College, Kretzer spent three years working and training with Olympic and NCAA champions at Imagine Swimming, and the New York Athletic Club.

Kretzer is a 2006 graduate of Bucknell University where he was a two-time Patriot League Conference Champion in the 200 fly and 100 backstroke. He was the class of 2006 Patriot League high point scorer as well. Kretzer also held the Suffolk County high school record in the 100 backstroke and was a five-time New York State Finalist.