Coaches & Directors

We are here to support your needs. If your questions are related to workouts, meets, events, goal setting, and other swimming related needs, please contact one of the coaches. For all questions related to administrative items, such as dues, safety, or policy issues, please contact Shannon Mackin.


Coaching Staff

Brian A Bolster

Head Coach/Aquatics Director


Brian is the founder, Head Coach and CEO of Osprey Aquatics.  Brian is a native of San Jose, grew up swimming locally and was a Junior National qualifier before accepting a swimming scholarship to SDSU.  Brian has been coaching for 27 years.  He has been the Head Coach of Osprey Aquatics since the fall of 1996.  The team started with 26 swimmers and 2 coaches, it now has around 160 year round with 5 coaches.  During his career, Brian has worked with swimmers at every level, from cabana swimmers, to beginning age groupers to Far Western Champions, Olympic Trials swimmers and a Para Olympian, Jacque Mox.

Brian is known as an innovator and stroke technician in our sport, having invented the Bolster Swim Paddle which is sold worldwide.  Under water speed is one of his specialties.  Linnea Mack won short course Junior Nationals in the 100 fly in 2013, in large part because her UW speed was world class.  

Brian’s has coached numerous swimmers ranked in the top ten Nationally.  He was named a 2014-2015 National Junior Team Coach for USA Swimming after Linnea Mack made the team.  Forty five times his swimmers have won individual or relay events at Far Westerns.  They have broken 5 Pac Swim records, won CCS, been named high school All Americans and won individual events at Sectionals, as well as received college scholarships to Division 1 programs.  

Brian has been published in NISCA Swim Magazine, and been profiled in Swimming World.  He was a presenter for FINIS at the 2012 ASCA Coaches Conference and gave a talk on the topic of Speed Maintenance as the Winning Edge, how training the ability to maintain target length (stroke count), and target rate (tempo) is the key to maintaining speed and winning races at the highest levels.   

Brian specializes in helping swimmers improve their mental approach and mindsets through mental training.  He is fond of saying, “We are what we think about most.  Thoughts become belief and belief becomes behavior.”  Mental training is something the Osprey do all year round, not just before the big meets.  Developing a positive self talk narrative is critical to success.  Winners find reasons why they can, not why they can’t. The senior group does the most of this work, and all of his swimmers have a working understanding of what it means to compete in and how to enter a flow state when racing.   

Brian is a Level 4 ASCA coach.



Shannon L Mackin

Team Manager and President



Shannon will be stepping back from coaching this year.  As the team’s longest tenured coach after Brian, she begins her 19th year with the team and will continue in the administrative and organizational side of things. Shannon is an expert coach, understanding all facets of our sport.  She has coached nearly every level on the team from SOAR to the Senior 2.  With CCS consolation finalist as well as Far Western Finalists. 

Shannon is an ASCA level 3 Coach

Oliver M Mackin

Head Age Group Coach



Oliver coaches the Sr2/Pre Senior and Gold Groups.  This will be his 12th full year of coaching after 5 additional summers spent coaching during his college years.  Oliver has developed into an exceptional coach who understands the stroke mechanics, energy systems, dryland, and sports psychology in a manner that sets him apart from most other coaches.  He is also capable of insightful observations and suggestions that not only benefit him, but our entire staff as well.  Oliver has trained a CCS finalist, nationally ranked swimmers and many Far Western Finalists over the years.  Oliver also manages our swim lesson program and has been a big part of it’s success. 

Oliver is an ASCA level 2 coach.

Ian J McAlister

Age Group Coach


Ian is one of our home grown coaches.  Ian started swimming with the Osprey in 2003 and swam for 6 years.  As a swimmer he was a Far Western finalist and swam on the Western Zone team in 2007. He began his coaching with us in 2009.  Ian now coaches the Bronze and AGE (Age Group Elite), however he has coached most all levels leading up to his current position.  Ian has a swimmers knowledge of the sport and is becoming a good motivator. 

Ian is an ASCA level 2 coach.

Samuel A Esbenshade

Age Group Coach


Sam began his coaching career with Osprey in 2016. He swam for the Osprey for 11 years, the last 4 were with Brian in the Sr. group, where he had success and made finals in the 200 breast at short course Far Westerns.   Sam knows our system very well, has a good eye for stroke mechanics and has demonstrated exceptional ability while teaching young people in our swim lesson program and managing the day to day works of the lesson program since 2017.  Sam’s intelligence, growth mindset, integrity, work ethic and understanding of the sport will serve him and the team well.  Sam will coach the Varsity, Copper, and the Silver groups.