Coaching Staff
Brandon Voorhies Head Coach/CEO

Brandon Voorhies joined the Cincinnati Marlins staff in September of 2021. He currently serves as Head Coach & CEO and coaches the National group while overseeing the whole program. In a short time with the Marlins, Brandon guided 15&under swimmers to qualifying times for Sectionals, Futures, and ISCA championships, as well as 12 swims ranked in the top 50 for USA Swimming.

Brandon previously served as Head Age Group Coach at Countryside YMCA where he coached from 2018-2021.  He has developed many swimmers to JO and National levels and has assisted in coaching swimmers to Y National top 8 finishes and USA Top 20 rankings.

While coaching at Countryside Brandon spent two seasons as the head coach of Indian Hill's high school swim team where he lead the braves to two top 10 finishes at the State Championship. His teams were district champions for the boys in 2018 and 2019, and for the girls in 2019. He was named Cincinnati's high school swimming coach of the year in 2019.

He attended Ohio State University where he was president of the club swim team for two years.  During his presidency, the club won the CCS Combined National Title, with their men's team taking first place and women's team taking second place. While serving as President of the Ohio State Club team, he and 9 other club presidents from around the country met and formed the governing body for College Club Swimming that exists today to support and serve the interests of college club swim programs. 

Brandon will be an outstanding fit with our Marlin team. He will work very hard to see all swimmers in the program achieve the highest levels. Brandon's philosophy on coaching is to meet swimmers where they are each day and push them towards greatness.

Hailey Olson NKU Site Lead - Senior

Hailey is from Cincinnati, Ohio, where she swam and coached for the M.E. Lyons Anderson Barracudas. She  graduated from Denison University with a Bachelor's in Psychology, and she swam for the varsity women's swim team for four years.  Hailey brings her passion for swimming and her enthusiasm for coaching to the Marlins at NKU.

Mavis Bushelman Five Seasons Site Lead - White Group

Maggie has been coaching swimming for over 12 years. Maggie has been with the Marlins since 2019. Since her start with the team, she has coached all ages 14 and under and she has coached at all 3 of our Marlins locations. Since its inception, Maggie has been a key part of our para swim group, the Platinum (formerly White) group. In the time since the group began in 2020, she has led a swimmer to  back to back  individual Junior State Championships. For her work with the White group, Maggie was a top 3 finalist for the Growing Abilities Award  in the summer of 2022. This award is  given each year by Redwood NKY. In addition to her experience here at the Marlins, Maggie has coached at SWAT in Mississippi, Highlands High School and several summer club programs in Northern Kentucky.

Matthew Harrison Full Time Coach - Keating Senior & Blue

Matt has been coaching swimming for over 15 years.  Matt has coached with Blue Ash YMCA, Countryside YMCA, as well as the WTRC Sharks.  Matt also coaches high school swimming. He spent 13 years as an Assistant Coach at his Alma Mater Moeller High School. In his first season as Head Coach at Indian Hill High School, he led the Boys team to the 2020 Division 2 State Championship, the first in school history!


Matt has received several coaching awards recently including - 2016 YMCA of Greater Cincinnati Age Group Coach of the Year, 2020 Cincinnati Hills League Coach of the Year, 2020 and 2021 Cincinnati Enquirer Division 2 Coach of the Year


Adam Warner Full Time Coach - Keating Senior & Gold

Adam began his coaching career as the Head High School and Middle School Coach for Huron School District in Ohio from 2010-2013. He then continued his coaching career at Wapakoneta High School and YMCA until 2021. In his time coaching high school swimming, Adam helped over twenty-eight state qualifiers achieve nine podium finishes, fifteen school records and numerous national level cuts.
After coaching high school swimming, Adam has served as the Head Age Group Coach for Countryside YMCA. In his two seasons, he helped swimmers achieve their YMCA national cuts, top ten team times and records.
Adam began his own swim career with Vacationland Swim Club based in Sandusky, Ohio and swam for Norwalk High School (2006). He still holds two team records in the 200 IM and 100 breaststroke. Adam continued his swim career with Hiram College. He has held seven school top ten times in the breaststroke, backstroke and IM events. Since 2011, Adam has competed in U.S. Masters Swimming events and has achieved nine individual top ten times in his age group, including being a part of two FINA world top ten relays.
Aside from his swimming career, Adam served in the United States Army from 2013- 2017 as an Operations Officer stationed in Fort Carson, Colorado and Fort Leonard Wood Missouri.

Matt Williams Full Time Coach - NKU Blue & Silver

In his youth Matt swam for Club Wolverine for seven years, and competitively for an additional seven before that. As a club swimmer he was a member of the CW national team for two years. In highschool Matt set his first school record as a freshman, and qualified for three state meets, placing as high as second. He was also voted Detroit’s ‘Mr Breaststroke’ and ‘Mr IM’ his senior year. In 2019 as a second year captain he led the boys to their only league title, and highest finish at states in school history (7th). 

In college Matt Attended and swam for Xavier University for 3.5 years until his medical retirement. He was All Academic Big East for three years. He majored in Political Science and Philosophy and graduated in the spring of 2023. 

Matt has been with the Marlins since the summer of 2021. He has worked as an assistant and lead coach for Red 2, a lead coach for Silver at the NKU site, and head coach for Mercy Montessori. Matt’s swimmers have achieved many Junior Olympic, ISCA and Zone cuts.

Aaron Dorfman Keating National Assistant

Aaron has been involved with the sport of swimming for almost 30 years.  He grew up in Colerain Township and started swimming for Orchard Hill Swim Club (where he was in the exhibition heat every single meet). At age 14, he committed more to the sport (backing off from cello and other sports) to focus more on swimming.    He swam competitively for Powel Crosley YMCA and was a Y National qualifier in both the Spring and Summer.  Aaron swam for the University of Cincinnati and graduated with a degree in Dietetics.  He then went on to complete his dietetic internship at Marshall University and a Masters in Nutrition.

Aaron has coached at Clippard YMCA, Gamble Nippert YMCA (with Coach Brad – 2000 YMCA LC Champs) and he founded the Mercy HealthPlex Sea Wolves.  Under Aaron’s leadership, the Sea Wolves grew from five swimmers to over 285, two training sites to four, two coaches to 14, jumped from a 3,000 ranking to the top 150 nationally, qualified an Olympic Trials athlete (high school swimmer) in 2015, achieved multiple top 10 finishes at the Junior Olympic meet, trained multiple state champions, coached LSC record holders and was selected to attend the USA Swimming Diversity Clinic in 2015.

Aaron has a full time job in career development for a real estate brokerage in Ft. Wright, KY.  He lives in Anderson Township with his wife and children.



Jeff Stueve Keating National Assistant
Jeff joined the Marlins in the spring of 2017. He was previously an assistant coach with the Countryside Torpedoes from 2003-2017. From 2003-2007 he was the lead coach for the 11-12 age group and from 2007-2008 the lead coach for the 13-14 age group. He was an assistant National Group coach from 2004-2017. He was the Head Coach at Mount Notre Dame High School from 2011-2013. He is a Magistrate at Warren County Probate/Juvenile Court. Jeff and his wife Jenn have four children.
Mariann Strenk Keating National Assistant

Mimi Strenk will be working with the National Group. Before coming to Marlins Central, Mimi was Head Site Coach at Marlins West where she coached the Gold group.  Prior to coaching for the Marlins, she coached at OHST for 4 years. Mimi also coached at McAuley High School for 4 years and was named GGCL Coach of the Year twice.  She also coached at Oak Hills Swim and Racquet Club. Mimi swam for Gamble Nippert YMCA, Mother of Mercy High School, and  St. Louis University where she swam on an athletic scholarship.

Andrew Gantzer Keating Senior & Bronze

Andy swam with Oak Hills Swimming Torpedoes early in his career.  While attending Oak Hills High School he was a three time State Qualifier, named GMC Swimmer of the Year and team MVS (most valuable swimmer).  After high school he attended Eastern Michigan University.  While a member of the swim team as a freshman he placed 3rd in 200y Freestyle at MAC Championships and was a member of the gold medal 200y, 400y, and 800y Freestyle relays.  Sophomore year he placed 7th in the 200y Freestyle and was a member of the 1st place 800y Freestyle relay. Sophomore year the team was the 2007 MAC Champions. Both years he earned second team All-Conference recognition.
Andy has coached with the Oak Hills Swimming Torpedo's as well as Moeller and Mt. Notre Dame Swimming.  He has specialized coaching in all strokes and all distances.  He is knowledgeable in the sport of swimming and strives to keep learning.  He likes to concentrate on technique and the mental aspect of swimming.
In his off time he enjoys going to Reds games, playing softball, visiting friends from college, and being home with his family.    He lives with his wife Heather, and his daughter Kaylie in Delhi.

Jeong Tae Ok Keating Senior

JT has been coaching swimming for the last 7 years. He was a nationally competitive swimmer in South Korea for IM, distance freestyle, and breaststroke when he was a youth and has coached with Wichita Falls Elite Swim Team (TX), Lima YMCA Barracudas (OH), Lima Shawnee High School Boys & Girls Swimming and Boys Tennis (OH), and the Westside Waves (OH). He obtained his PhD in Engineering Science (Mechanical & Electrical Engineering concentrated) from Louisiana State University in 2011, and has taught multiple core courses of mechanical and electrical engineering such as Dynamics, Materials Science, Fluid Mechanics, Heat Transfer, Measurement and Instrumentation, System Dynamics, Machine Elements Design, and Capstone Projects at Midwestern State University (Wichita Falls, TX) and Wright State University (Celina, OH). He's been teaching DC/AC Circuits, Electronics, Fluid Power in the Department of Engineering Technology at Shawnee State University (Portsmouth, OH). JT's research interests include Micro- and Nanoscale Engineering, Smart Electromechanical System, and Machine Learning based Swimming Coaching Assistant Robot. He would like to help Cincinnati Marlins swimmers learn how to swim more efficiently while creating a fun environment with continued technical progress. He also has two sons, Niel (Senior) and Aiden (Sophomore) that are swimming with the Cincinnati Marlins.

Austin Theobald Keating Gold

Austin joined the Marlins coaching staff in the Fall of 2022. Austin is a realtor in for Coldwell Banker in the greater Cincinnati area. Prior to joining the Marlins staff Austin was the assistant head coach from 2018-2019 at the Lakota YMCA summer club. 

Austin's background is swimming is extensive. He swam for Miami university on their varsity team for four years. During his time at Miami, Austin was voted team captain and the team won the MAC championship. Austin grew up swimming for the Countryside YMCA Torpedoes in Lebanon Ohio. He was specialized in Freestyle and was a 7-time Y National qualifier and was a part of the 2014 and 2016 YMCA National championship teams. A graduate of Moller High School, Austin was a three time State qualifier and four year varsity letter-winner.

Austin brings energy and enthusiasm to every practice and looks forward to developing swimmers in the Marlins program.

Wiktor Serafin Keating Silver

Wiktor (Victor) joined the Marlins in the fall of 2021. From 2017 to 2021 he was an assistant coach, then a lead group coach for Gold (10-13 old) and Silver (8-11 old) groups, with the Western Wahoos in DE, when he relocated to OH.  He has consistently developed multiple Junior Olympics and Zones qualifiers.   Wiktor has been involved with the sport since childhood. He started swimming at the age of 6 in Poland and continued to swim after a move to Canada.  Swimming achievements consisted of qualifying for short course junior championships in Poland, international meets in Russia, Czechoslovakia and various provincial and high school meets in Canada, attending both short and long course meets. Outside of the pool,  Wiktor is employed by GE Aviation in an engineering role and have over 30 years' experience working for big and small companies in various engineering roles. Wiktor and his wife Agnes have two kids who will be swimming with the Marlins.


Alex Schmidt Keating Bronze
Riley Dungan NKU Bronze
Amanda Sequeira Five Seasons Silver
Anthony Roberts II Five Seasons Bronze

Tony Roberts comes to the Marlins from the staff the Sycamore Flying Fish.  Tony has over 15 years of coaching experience working with young swimmers.  His enthusiasm and knowledge of the sport has earned him respect among Cincinnati’s coaches, parents and swimmers.  An Indiana University graduate, Tony also teaches math in the Cincinnati Public Schools.

Jennifer Hedger Business Manager