Head Coaches 

Erin Hoffman

Head Site Coach - Presidio

Erin has a love and enthusiasm for the water she wants to instill in every swimmer she works with. From the age of eight growing up in Michigan, she has been a competitive age-group swimmer, team captain, water polo player, intercollegiate swimmer at Wittenberg University, masters swimmer and coach with over 30 years of water training.  Whether inspiring swimmers to learn their first flip turn, master butterfly, or set records--her goal is to make a difference in the lives of everyone she coaches. When not on deck or in the pool herself, she spends time with her husband Vasilios and twins Amelia and Hayes who keep her life fun and busy. 


Natalie McArthur

Head Site Coach - Stonestown


Natalie began swimming competitively at the age of 12, and quickly found a love for the water. She swam with 2 club teams down in SoCal, Roadrunner Aquatics and Rio Bravo Greeley Swim Team, along with being on her high school varsity swim team. Natalie's favorite events are the 200 Freestyle and the 500 Freestyle. She has taught swim lessons and worked in aquatics for 6 years and has found her passion for teaching. Natalie hopes she can continue to inspire kids and help them find a love for the water as she did. 

Greg Lee

Head Site Coach - Chinatown


Gregory is the coach of the Chinatown YMCA Swim Team, where he started the branch's team in 2012. Gregory was in the founding group and Team Captain of the Presidio YMCA Pacific Aquatic Club Swim Team in 2003, and swam with the team through 2010. 

During his high school years, he swam competitively at George Washington High School. He attended the University of San Francisco and graduated Cum Laude in May 2014, where he received his Bachelor of Science Degree in Finance along with double minors in Computer Science and Chinese Studies. 

Gregory is also the coach of the Masters Swimming Program at the Chinatown YMCA. He enjoys coaching and working with swimmers of all ages.


Assistant Coaches


Melissa Au


Melissa has swimming in her blood. Melissa began swimming on the YPAC team when she was ten years old. Her most memorable moment is all the yoga drylands and running up the Lyon Street Steps. Never again. Now that Melissa is no longer swimming competitively, she coaches the yellow lane. Melissa is studying at San Francisco State University to reach her goal of being an elementary teacher. Melissa is also a YMCA camp counselor during the summer. Fun fact: In Melissa's past time, when not coaching, she is playing video games or watching musical shows.


Kristin Hill


Kristin has years of swimming and water polo experience, along with over four years of lifeguarding and swim instructing experience, and two years coaching both youth swimmers and Masters swimmers. When Kristin isn’t at the pool she’s either at SF state where she studies Business Administration and Earth Science, reading, or adventuring around her new home of San Francisco.



Aditya Jalihal


Coach Aditya has been involved in competitive swimming for more than 15 years. His swim experience ranges from age group swimming to the collegiate level. He has worked under internationally recognized coaches and trained with Olympic level athletes. His swim specialties are mid-distance freestyle and individual medley events. A student of the sport, he is bringing a passion and enthusiasm for the sport of swimming to YPAC that he hopes will positively impact the next generation of athletes.


Cara Koopmann


Cara started on swim team when she was seven years old. Every summer she spent more time in the pool than on dry land.  She swam competitively for twelve years, including four years on her high school varsity team. Her favorite races were 200 yard breaststroke and 500 yard freestyle. She has been teaching kids to swim for five years, and has been with the Y for two years. She has a Marine Biology degree from Texas A&M, and hopes to inspire her swimmers to love the ocean as much as she does.


Kory O'Rourke


Kory is on her third stint as a coach for YPAC.  She was one of the founding coaches of the Presidio YMCA Pacific Aquatic Club Swim Team in 2003, and the creator of the two original YPAC cheers "P is for Persistence" and "Right Patch, Left Patch!"

Kory swam and played water polo from a very young age.  She competed in both sports in High School, and played Water Polo for Golden West Junior College where she was Team Captain of the State Championship team.  She went on to play Water Polo at the University of Southern California, where she was a part of the NCAA Championship team in 2000. 

She has a Bachelor's from USC, a Masters from SFSU, and is a public school teacher in San Francisco.  Kory's daughter Keaton is a proud member of YPAC! 

Sandie Stringfellow


Dr. Sandie Stringfellow is in her third year as an assistant coach at YPAC. Coach Sandie swam for the Upper Main Line YMCA (UMLY) in Berwyn, PA for 13 years and co-captained the team the first year the women's team won YMCA Nationals. She previously coached at UMLY. Sandie swam for Harvard, where she was a four-year varsity letter winner. Coach Sandie also swam for the University of London when she was a master's student at the London School of Economics, and was a finalist at British University Nationals. She coaches Green, Blue and Black lanes and is the parent of a Green Lane swimmer and a preschooler in swim lessons at the Y.


Tennyson Zhu


Tennyson was a competitive swimmer for twelve years at the Balboa Sharks swim team and moved onto high school competition for Lowell High School. His favorite events included sprint Freestyle and Butterfly. After four years on the Boys Varsity team and one year as Co-Captain, he began working with children and found his passion for teaching. Tennyson hopes to contribute to a swim community that cares and supports one another just as he experienced in his past. Tennyson is currently a Finance major studying at the University of San Francisco.



Cary Fulbright

Volunteer Assistant Coach - Presidio

Cary has been a volunteer assistant coach for the YMCA Pacific Aquatic Club since 2005, and has coached swimmers for over 20 years.  Cary swam competitively throughout his childhood and was captain of his high school swim team.  He taught swimming for five summers at Trinity School Day Camp in New York City, and also helped coach the Trinity Aquatics Club for two years.  Cary is a masters swimmer at the Presidio YMCA and an ASCA Level 2 certified coach.


Kate Eaneman

Presidio YMCA Aquatics Program Director and YPAC Swim Team Supervisor