Peter Sotis

Founder and Owner, Add Helium, LLC
Owner of Forum, “The Deco Stop”
Owner of Forum, “Rebreather World”
IANTD Instructor Trainer Trainer Certification
IANTD Instructor Trainer Certification Certifications – Cave, Technical Cave, Trimix, rEvo, Optima, Hollis Prism2, Hollis Explorer, Megalodon, Pathfinder, Poseidon, Titan
IANTD Instructor Certifications – Evolution, Inspiration, Sentinel, Hammerhead, KISS, Flex Extreme, Advanced Wreck, DPV, Full Face Mask

Peter is qualified to develop divers, instructors and instructor trainers to any level. As the Director of Training for Add Helium, he is training others and is developing training programs that reflect his experience and dedication to the sport.

Peter’s passion for rebreather diving and exploring has lead to the development of the Add Helium dive team and the Add Helium Science Council. This highly trained team consistently pushes the limits as they explore deep walls in excess of 600 feet, deep wrecks and extreme caves. Peter is currently leading a cave exploration in Quintana Roo, Mexico, also known as the “Pit Project”. Its progress can be followed on the Add Helium website.

Peter is the inventor of TruDive, an innovative and accurate method for dive planning. This system is currently being built into a platform for general use and will be released in the near future.

Peter’s vision was to create a professional organization that allows diver’s to develop to their greatest potential. Add Helium’s business model and all of its components are the culmination of that vision.

Emilie Voissem

General Manager

Emilie has over 15 years experience in public safety with the San Luis Obispo County, California Sheriff’s Department. In that time she has worked as a dispatcher, patrol officer, and public safety diver. Emilie began diving in 2010, which opened her eyes to the underwater world and traveling to new countries.

Emilie moved to Florida about 5 ½ years ago to focus on diving and a less stressful way of life. She became a Divemaster in early 2013 and continued her diving education to include open circuit technical diving as well as rebreather diving. She has been a technical divemaster for a local dive shop and has worked for Add Helium for over 4 years where she has had a variety of different roles. Emilie is able to assist you in any aspect of Add Helium business.

When not at work, Emilie can be found diving, working on a boat, or at home taking care of one of her three saltwater aquariums.

AH 4.18 Image - robyn lengrevin
Robyn Langevin

Customer Service Manager

Robyn brings over a decade of experience as an office administrator as well as business management. She loves being part of the diving industry. She plays an integral role in customer service and organizational strength of Add Helium.

In the beginning stages of scuba diving, Robyn became Open Water Certified in July of 2017. She intends to continue her diving education and become an advanced diver. Her goals is to observe and study sharks in the deep!

In her free time she reads, scuba and free dives, does yoga, and takes care of her two cats and her red-eared slider. Robyn uses her experience and love of sharks to advocate on their behalf. Her hope is to find ways to help society become more aware of the necessity of sharks in our ecosystem and stop the senseless killing of them.

Robyn’s attention to detail, cheerful demeanor, and love for all things water makes her the perfect person to handle customers at Add Helium, so give her a call today!

Maggie Lebron
Maggie Lebron

CCR Diver, OC/OW Instructor

Maggie joins Add Helium with many years of customer service experience. Maggie’s primary focus to assure that a client’s training experience with Add Helium is smooth and is going according to plan. Since details do make a difference, Maggie is coordinating everything a client may need. From class materials and equipment, to hotel reservations, and car rentals, Maggie is here to make your time with Add Helium great.

Ryan King
Ryan King

Director of Educational Materials
CCR Normoxic, CCR Cave, OC Instructor

Ryan has always been fascinated by the ocean. He grew up in New England and began diving in 1996. It didn’t take long for him to pick up his first camera and, for more that 25 years, he’s been exploring and photographing caves, wrecks, reefs and other sites from Canada to the Caribbean and Mexico. In 2011 he moved to a rebreather and has never looked back. Recent trips have taken him to explore wrecks in the Great Lakes and Stellwagen Bank off Massachusetts, caves in Florida and Mexico, and other sites throughout the Gulf of Maine and Eastern Canada.

Ryan has over 15 years experience in education. During that time, he has worked as a SCUBA Instructor, Middle and High School Science Teacher, an Educational Technologist, and an adjunct lecturer at the college level. He has a passion for taking complex topics and making them accessible engaging for all students.

Ryan helps to develop all of the specialized lectures, powerpoint presentations and educational materials used by Add Helium.

Robert Johnson
Robert Johnson

Dive Instructor – Dive Rite O2ptima, rEvo, Poseidon, CCR Trimix, and OC Trimix

Robert always felt a kinship to the ocean and for his 13th birthday his parents provided for his open water certification. Eventually, Robert became intrigued with rebreathers and at the age of 19 decided to develop his own. Since then his design has undergone numerous changes and upgrades, as it continues to be a work in progress.

Diving opened up the opportunity to travel and Robert has enjoyed many trips to Bonaire and Curacao. He moved to Florida in 2010 from Maryland and began working as a dive master. As he is drawn to the deep sea doing technical dives, his goal is to teach others how to dive safely.

AH 7.18 John Entwistle
John Entwistle

Dive Instructor Assistant, CCR 100 meter Certification

Prior to coming to Add Helium, John was a middle school Earth science teacher. He temporarily left teaching to serve in the U.S. Army as a Missile Command and Control Specialist. After the Army, he returned to teaching high school Physical Science and computer science teacher, and science department chairperson at Damascus High School in Montgomery County, Maryland. Due to his ground-breaking efforts incorporating computers into the classroom, he was invited to work with NASA at NASA Goddard Space Flight Center, Greenbelt, Maryland, then as a contractor at NASA Headquarters in Washington, DC., and finally as the Technology Services Coordinator for a NASA project administered at NASA Glenn Research Center, Cleveland, Ohio.

After moving to Florida, he eventually became certified as an OC Normoxic and cavern diver. After many dives lugging around doubles on his back and bailout bottles on his side, he decided to try a rebreather. After his first rEvo CCR dive, he knew he would become a rebreather diver. He continued his diving education with Add Helium until he earned his 100 m CCR certification.

Since becoming a diver, John met some great divers on several live aboard dive trips including Nassau, Exuma, the Bahamas, Socorro, and the Red Sea, among others. He’s also been to Mexico where he dove the famous cenotes as well as drift diving at Cancun. He enjoys using photography and image improvement techniques to document his diving adventures.

Doug Ebersole
Doug Ebersole

KISS CCR/SCR Instructor

Douglas Ebersole, MD started diving in 1974 and is an experienced rebreather, technical, and cave diver. He began teaching recreational scuba diving in 2002 and became a technical diving and rebreather diving instructor in 2005. He is currently a very active rebreather instructor on several different units and teaches rebreathers from entry level to CCR trimix. Doug’s “real job” is as an interventional cardiologist for Watson Clinic LLP at Lakeland Regional Medical Center in Lakeland, Florida where he specializes in coronary and structural heart interventions. He has a special interest in in PFOs and diving and diving with coronary artery disease. He has lectured around the world on various topics in diving medicine and is a cardiology consultant to Divers Alert Network (DAN).

Dr. Edwin (Rick) Slott, MD, PhD
Dr. Edwin (Rick) Slott, MD, PhD

Member Add Helium Science Council
CCR Trimix, CCR Cave, rEvo, Evolution

Dr. Slott is a Diplomat of the American Board of Emergency Medicine and holds a PhD in genetics. Over the years, Dr. Slott developed additional interests in hyperbaric medicine and exercise physiology.

As an avid CCR diver, Dr. Slott is certified on multiple units up to full trimix.

Dr. Slott is an invaluable member of the Add Helium Science Council. With his unique background, talent and interests, Dr. Slott joins the team that aims to educate divers regarding all physiological aspects of diving. Current and future postings on the topics of fitness and diving can be found on the Add Helium Website’s Science Section.

John "Ozzy" Osgood
John "Ozzy" Osgood

Member Add Helium Science Council
LMT, NMT, Personal Trainer
CCR Trimix Diver

Mr. Osgood is a personal trainer and a licensed neuromuscular massage therapist. Ozzy utilizes his expertise to implement movement specific exercises optimizing one’s body for diving. He believes in preparing the body for the exertion of diving

John’s expertise is essential to the Add Helium dive team. His 15 years of diving experience coupled with his professional background brings about a unique and effective approach. Acting as the team personal trainer and nutritionist, his participation is a key component in preparing the team.

John’s input is also invaluable to the Add Helium Science Council. He provides insight into much of the research information as they collaborate over the latest findings pertaining to diving.


Michael has joined the Add Helium Service Team and brings with him many years of experience. He began scuba diving in 1998 and is currently a Master Scuba Diver Trainer. He was attracted to the mystery of the sea and the sunken treasures she held. He sought these treasures however never found the riches he was looking for until one day he realized the real treasure surrounded him from the very beginning. The beautiful coral reef, full of color, and the fish around him were treasure enough. He began his scuba instructor career to show others what lies below the surface and the beauty we are surrounded by.

Michael has years of equipment service experience and continues to grow his education about rebreathers. He strives for excellence and knowledge in the industry and is a great addition to the service department.


As the Add Helium dive team began to explore deeper and further, they were not satisfied with the “status quo” of information. Training agencies and industry experts clearly disseminated outdated and unsubstantiated information.

We all need information based on valid research to achieve optimal dives.

The information you seek, the information we all seek, is here on our site – take a peek and improve your dives.

21 Feb
How Do You Learn Best? Improve Your Dive Learning Experience

Feb 21st, 2018 by admin in Business ,Rebreather Diving

Ever wondered how we learn and how we retain what we learned? Have you noticed that you will retain less than 100% of the material presented? Furthermore, because you zone out, get distracted, or do not comprehend, you are not even cognizant of the things you see and hear during the class. Every time a,

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Why Pockets?
08 Jan
Why pockets?

Jan 8th, 2018 by admin in Business ,Rebreather Diving

During a dive, clipping gear to D-rings provides easy access to items we use most often. Reels, lights, primary SMB’s and line arrows are good examples of items we use often on a dive. However, we bring some items “just in case”. Many of these items could present an entanglement issue if stored externally. Pockets are often the best place to store these items. For example, spare masks, gloves, secondary cutting

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05 Jan
2nd Annual Add Helium Expedition Seminar Trip Report

Jan 5th, 2018 by admin in Rebreather Diving

Since last year’s event was a full success, we hosted it again at Dive Tech in Grand Cayman. Conditions were terrific for this time of year. The water temperature was at a balmy 81 degrees all the way down to 400 feet and the air temperature ranging mid 80’s during the day and mid 70’s in the evening. Some of the participants from last year’s event decided to return for another round thus giving the group a nice mix of new and old acquaintances. This year we had Inspirations, rEvos, Megalodons a

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