Schrotenboer took over the swimming and diving programs prior to the 2015-16 season, and the Tornado showed drastic improvement in his first year. The Tornado set and resest school records 26 times over his first season, breaking nine women's records and four men's records.

At the Appalachian Swimming Conference Championships, the Tornado women finished ninth while the men took 12th. The women set school records in the 50, 100 and 500 yard freestyle as well as the 100, and 200 yard breaststroke and the 100 yard butterfly and the 100, 200 and 400 yard individual medley. On the men's side, Quenton Lyons set school records for the 200, 500, 1000 and 1650 yard freestyle races. Nicole Maldanado was named Appalachian Swimming Conference Swimmer of the Week on October 5 and Jess Vargo was selected King University's Rookie of the Year.

Prior to King Schrotenboer spent three years as an assistant coach at Calvin College, where he helped lead the Knights men's and women's programs to a combined five MIAA Conference championships. While at Calvin, Schrotenboer helped in every aspect of the program, from helping with recruiting to teaching the student-athletes at practices and meets and helping develop conditioning plans for pre and postseason workouts.

He graduated from Grand Valley State University, where he was a 15-time NCAA Division II All-American and helped lead the Lakers to two Great Lakes Intercollegiate Athletic Conference championships and served as a team captain. Schrotenboer then earned his Master in Educational Leadership and Policy Studies from Iowa State University.