Board of Directors

The K9 Navigators Board of Directors is comprised of individuals committed to enhancing the service dog world for veterans, first-responders and their families. We are proud to have the following individuals serve on our Board of Directors.

 Pictured here with his mother.

Pictured here with his mother.

Tyler D. Sexton

President / MD, CHWS, CHT, DMT / Service Dog User

Dr. Sexton earned his medical degree from the University of Sint Eustatius School of Medicine specializing in pediatrics and hyperbaric medicine. He completed his pediatric residency at the University of South Alabama. Since 2003, Dr. Sexton has been an international motivational speaker. Dr. Sexton has spoken hundreds of times raising awareness about overcoming adversity for the disabled. He has written a book entitled God Bless These Little Legs and been featured in numerous books, articles and radio/television broadcasts around the country. Some of these programs include ABC’s 20/20, 700 Club, The God Squad, Hour of Power, The Helpline and Focus on the Family. His goal is to impact people by instilling in them an attitude of achievement regardless of the disability or situation. He strives to be a doctor who gives hope to patients instead of worst case scenarios.

His interest in Hyperbarics was initially due to his diagnosis of Cerebral Palsy. Dr. Sexton was told that he would never walk, talk or even see. Defying these odds and undergoing 16 surgeries, he pursued his passion of scuba diving and has climbed the ranks of recreational scuba diving and turned his passion into his career as a Hyperbaric physician. Dr. Sexton has published many papers focused on Hyperbaric Medicine and its medicinal effects in many clinical applications. Dr. Sexton mentors children with disabilities and works with many special interest groups educating them in the field of Hyperbaric Medicine. He uses this knowledge as a physician by treating countless individuals suffering from decompression illness and other hyperbaric clinical applications in the United States and abroad for anyone in need of it.

He is an American College of Hyperbaric Medicine approved training provider and also had courses approved by the National Board of Diving and Hyperbaric Technologies. Dr. Sexton is the Vice President of the American College of Hyperbaric Medicine, one of the two national professional organizations dedicated to serving as a medical specialty society. Dr. Sexton focuses on adult and pediatric wound care and serves as Chair of Pediatrics and Wound Care and Hyperbaric Medicine. Dr. Sexton has extensive wound care experience and is a member of the American Professional Wound Care Association and has achieved the honor of being appointed the Status of MAPWCA. The “Master” designation was initiated in 2010 and serves as a mechanism to recognize key opinion leaders who have impacted wound care through education, research and advocacy. These honorees are selected by an appointed APWCA committee and then approved by the Board of Directors.

Dr. Sexton Also holds certification as a Certified Hyperbaric Wound Specialist by the American Board of Wound Healing (ABWH), a Certified Hyperbaric Technologist (CHT) and a Diver Medic Technician (DMT). Dr. Sexton also holds Certificates of Added Qualification in Hyperbaric Medicine and Wound Care by the American Board of Wound Healing. He also specializes in bringing Hyperbaric Medical Clinics to parts of the world that otherwise would not seem to be possible. 

Tyler has been a service dog user for over 10 years. Danny, his first service dog was trained by Mike Sergeant and was the catalyst to their friendship. The innumerable blessings that come with the a service dog is the reason Tyler joined forces with Mike in founding K9 Navigators. 

Dr. Tyler Sexton featured on a recent episode of ABC's 20/20

Mark Peniston


Mark Peniston is a licensed Certified Public Accountant in the states of Florida and Texas.  He holds both a Bachelor of Science and Masters of Science in Accounting and has over twelve years of industry experience.  Additionally, Mark owns his own CPA firm, providing financial services to both individuals and small businesses.

Mark firmly believes in service to others and is very active in his community, serving on the board of his church as well as the local PTA.  He also believes in honoring those who have made the ultimate sacrifice in service to their country.

Mark currently resides in San Antonio with his wife and two sets of identical twin boys.

Jim Mathys

Chief Training Officer

Jim Mathys joined the Air Force in 1976, where he served at Strategic Air Command.  Jim’s father trained Guide dogs at Pilot Dogs for 60 years. Having grown up living in an apartment above one of the largest kennels, at that time, Jim was destined to train dogs. Sharing his father’s compassion for helping the visually impaired, in 1983 Jim followed his father’s example and began as an apprentice at Pilot Dogs for three years to become a certified trainer and instructor.  It was there at Pilot Dogs that he met Mike Sergeant.

From there Jim went to South Eastern Guide Dogs and worked as the Supervisor of Training under Mike Sergeant.  He left there and started Quality K-9 Services in Florida, providing training for police K-9 and competition dogs.  Jim was also an expert witness providing testimony and assessment in court cases involving dog bites.  Jim began training service dogs at this own expense under this Quality K-9 Services dog training business, which produced one of the first service dogs at Walter Reed National Military Medical Center.  Jim had to leave Florida and he then started working for America’s Vet Dogs, once again working under Mike Sergeant.  He obtained his ADI (Assistance Dog International) accreditation as a service dog trainer/instructor.  At America’s Vet Dogs Jim went from trainer/instructor to manager then when Mike left, Jim took over running the program. He was able to double the number of successful placements of service dogs with veterans.

During his time at America’s Vet Dogs, Jim saw a need in his local area for dog training and boarding so he extended his Quality K-9 Services to Georgia. Having known Mike Sergeant for many years, when Jim heard about K9 Navigators and their mission to provide service dogs to veterans, first responders, or their family members he wanted to be a part.  He now has trained and placed 20 plus dogs with recipients and feels that K9 Navigators adds a personal and individualized touch that separates them from larger assistance dog organizations.

Rebecca Fletcher

Growing up I always had a deeper connection with animals than people.  I started riding horses when I was 6, by the age of 16 I was training horses that had problem behaviors such as rearing, bucking, or running through the bit.  I also worked at The Perfect Pet Resort, which at the time was a newly opened kennel.  I worked there my junior and senior years of High School.  I attended college as an Equine Major for one year, though I did not complete college I learned a lot of valuable skills in caring and management of animals.  Growing up I had horses but not dogs, because mom did not want anything in the house that could breathe.  After I came home from College I moved into my own place and got my first dog.  Having worked at a kennel I knew what behaviors I did not like so I trained my pit-bull puppy based off how I felt he should act.

In 2010 I joined the Marine Corps and served as a Logistician until I was injured in 2013.  I went through two years of rehabilitation for my injuries, having to re-learn how to do pretty much everything for myself.  Being the dog lover that I am I knew the benefit of having a dog emotionally but I also began researching how a service dog could help me physically.  When I retired and bought my home I got my puppy.  I began reading and educating myself on service dog training.

A friend of mine, Butch, whom is the trainer at The Perfect Pet Resort put me in contact with Mike Sergeant of K-9 Navigators.  As I worked with Mike and my puppy my passion for dog training grew.  I began getting requests to train other peoples pet dogs and from there my Dog Training business grew successfully.  I met Jim Mathys the Chief Trainer with k-9 Navigators and have spent upwards of 300 hours apprenticing under him.  I am now the only trainer recommended by Animal Control in Queen Anne's County.I also am the sole trainer for and recommended by Queen Anne's County Shelter, I work closely with the shelter taking dogs that have been at the shelter too long or have been returned because of behavior problems and training them so that they can find good homes.

The benefits of a disabled person's service dog in insurmountable.  I am driven by my passion and love for dogs and my desire to help other disabled veterans find their canine companion just as I have found mine.