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The Early Evolution of Technical Diving - Overview

by Tom Mount Ph.D., Th.D.

Thanks to Hal Watts for contributing to this article

Tom Mount & Hal WattsHal and Tom discussing the evolution of technical diving. Both were early deep and cave divers/ explorers and educators.
Our friendship first started in the early 60’s.
A belief we share is that as one ages it is even more important to workout than when younger, Hal is 84 and Tom is just turning 81 in March (2020). Hal began working out when he was 12 and Tom has worked out since he was nine. Yes, we both have had physical challenges and feel our working out and attitudes enabled us to overcome them.
We both remain committed to safer technical diving and on-going advances in factors enhancing dive safety.

Curious, limit pushing explorers, had to develop dive techniques, equipment configurations and equipment modifications to survive their adventures. These developments evolved into an education / training system known today as Technical diving. Today’s Technical Diving programs train safer, knowledgeable and skilled divers based on the foundations gleamed from those explorers. Technical diving continues to improve with a side benefit of introducing portions of these developments into recreational diving increasing its safety.

As a community Technical Diving, continues to improve techniques, expand knowledge and contribute to equipment interventions. This article will present technical diving evolution, Existing state and foundation for its future. Technical diving provides a safer gateway into underwater exploration.

The first areas of Technical traing addressed were deep air, wreck and cave. Early accounts of cave diving begin in France and the UK with exploration of sumps using breath hold diving to bridge submerged area with additional dry passages. and putting candles in a container to get through wet sections of a sump. The British Cave Diving group formed in 1946 explored sumps and caves many with many members using oxygen rebreathers as well as other dive gear. This group remains active today and is the oldest cave diving group in existence. It was within France and the UK where the concept of sidemount cylinders and independent doubles first emerged.

In the USA cave diving started growing more popular in the early and mid-60’s. During this period exploration complications such as no pressure gauges, no Buoyancy compensators made dive planning more complex. To offset this early explores were quite accurate on knowing their RMV’s. and selection of dive cylinders and equipment to assist in buoyancy control. This led to searches to created better lighting, buoyancy control, and to the evolution of dual manifolds.


Hal Watts introduced a method of buoyancy compensation (BC) using Clorox bottles. Used properly the diver enlarges the neck of the Clorox bottle so that he can either blow into it or allow gas from the exhaust tee of his regulator to be exhaled into it, creating the desired buoyancy state. An indirect advantage of this approach is you could stop be any junk yard and pick up a BC Clorox bottle. Many of us converted to Jerry cans for additional buoyancy. The doubles of choice at that time were the old navy type single outlet manifold and some used independent cylinders as doubles. Wet suits were the primary diving attire until the dry suit technology evolved to a better level than in the early 60’s.

Early lighting systems evolved from lights in containers followed by commercially produced light of limited depth and brightness to home made lighting system and finally to the exceptional lighting systems of today.

An engineer who worked at Martin in Orlando produced a custom nicad battery in a small housing with the reflector and bulb attached the Hal Watts used in his deep diving group, the only disadvantage of this light was limited duration. Around 1964 someone produced a drawing enabling divers to make their own underwater lighting systems.

This consisted of a 6-volt motorcycle battery, that you would attach a plumber’s helper to with hose clamps and insert a par 36 light bulb into. The light bulb would have a wire lead attached to the bulb and alligator clips attached to the other end of the lead to attach to the motorcycle batteries positive and negative terminals the bulb was epoxied into the plumber’s helper. For longer duration dives a 35-watt bulb was used and on shorter dives some opted to use a 100-watt aircraft landing light bulb. The light was carried hanging from the divers neck by either bungy cord or line attached to the battery by the hose clamps that held the plumbers helper to the battery.

A few of the drawbacks to this system were:

  1. Battery acid leaking onto clothes etc.
  2. Would get shocked in used in saltwater
  3. Occasionally they would implode between 240 and 260 feet (73 and 79 meters)

In the late 60’s Frank Martz produced professional quality reels and lighting systems as well as inflator system for BC’s for cave diving.

(above) Tom Mount at Eagles nest 1969 Note Martz lights inside van, Martz reel on ground, Jerry Can for BC, single outlet valve on doubles, camera housing and flash bulbs.

Frank died on a dive in Benjamins Cave (blue hole 4) in 1971. On that dive Frank was wearing the newly released double 104’ (Frank and I had the first two sets in Florida-I sold mine as they were too negative buoyant for me) for the first time. Many of us felt the high negativity of those cylinders contribute to his demise. It is true these same type doubles became the standard for many cave divers as time passed and better buoyancy compensator became available.

(above) 1971 Benjamins cave (blue hole 4) this was the last dive Frank Martz ever made. Frank and Jim Lockwood were going to explore a passage Frank had found on our last trip there.
Zidi and I were to add line in the south passage.
Prior to the dive I had a premonition one of us would have an accident. Normally I listen to my intutition, but on this dive I did not. I felt because Frank and I had disagreed on whether we worked with George Benjamin filming that day and explored post the film work which was our agreement with George, Frank convinced George to ok the dive. So I thought my bad feeling was over our disagreement.
But I did continue o have the feeling as the dive stared. About 25 minutes in the dive I felt someone had died, it was not Zidi or I so as we exited we saw Jim, Jim and Frank had got into a bad silt out and Jim felt Frank passd him so expected to see him on the way out. Zidi went up to decompress and Jim and I doubled back to try and find Frank. We pushed our air to the maximum and returned to decompress (deco was on oxygen).

Hal Watts who was already a YMCA Scuba Instructor, formed the Florida State Skin Diving Schools then changed the name to Professional Scuba Association (PSA) in 1962. This association taught deep air to depths of 240 feet/72 meters. PSA was the first technical diving agency. (as a side note Hal talked me into doing by YMCA instructor program in 1964) Hal also formed a deep diver specialty group the 40 fathom Scubapros. Their name came from the fact that each Friday evening they went to a sink hole named Zuber Sink (Hal had the name changed to 40 fathom sink) which was 40 fathoms /240 ft/72 m deep.

Hal Watts, Tom Mount and David Desautels although not certifying people as cave divers did teach divers to dive into caves prior to formal cave dive training agencies.

In addition to PSA, Hal completed IANTD traing programs in 1992 and 1993 up to the level of Instructor Trainer in Advanced EANx, Advanced Recreational Trimix, Normoxic and Trimix, CCR MK 15, Dolphin SCR and all gas blending levels During training Hal referred to trimix as using “Girly Gas “.

In the 60’s the springs and caves in Florida due to their clear warm water beckoned to divers who had no understanding of the hazards of being in a wet cave. A few of these hazards included silt outs (loss of visibility) mazes (multiple passages) and inability to ascend directly to the surface. This led to diving fatalities and numerous negative articles on cave diving combined with political threats to close caves to the public or ban diving into caves. The accident that was the most dramatic occurred at Ginny Springs when 5 college students lost their way and died inside Ginny cave. We recovered those students who appeared to follow the cave wall but unfortunately the wall selected was the inside wall of the passageway and just led them in circles until in zero visibility they exhausted their air supplies and died. The news outlets highly publicized that accident. As a resulted, the property owners contacted me to see if the cave entrance could be closed off, and if it could be, they would still allow us to have excess to Devils Eye and Ear. To accomplish this our team of Tom Mount, Ike Ikehara, Jim Fishback, Jack Banbury and Jim Nangel took on this challenge. The result was the installation of the grate divers visiting Ginny see today. Jim Nangle spent 6 hours welding the frame together as the rest of us carried the rebar down and fit it into place

Post this event Tom Mount, Dave Desautels, Dale Malloy, and Larry Briel and Hal Watts founded the NACD (1968). NACD was the first USA cave diver training agency and published the first cave diver textbooks The Cave Diving Manual by Tom Mount, followed by Safe Cave Diving (lead author Tom Mount with multiple contributing authors including Sheck Exley. The NACD also developed the first organized Cavern and Cave Diver courses.

Note in 1971 Sheck Exley was instrumental in forming the NSS/CDS.

IAND was formed by Dick Rutkowski in 1985 introducing nitrox to divers, Tom Mount became president of IAND in 1990 and updated it to IANTD the first full range technical diving agency. Deep Air-Trimix, Wreck, Cave, Mine. IANTD ALSO became the first agency to teach CCR.

In 1991 Tom, brought both Billy Deans and Bret Gilliam into IANTD as officers. Billy Deans was an accomplished wreck diver and pioneer of trimix diving. Consequently, he became an instructor then instructor trainer. Bret had a reputation as an outstanding deep air diver and in marketing. As part of his marketing director responsibilities Brett attended dive shows promoting IANTD. Bret completed his IANTD Technical Instructor IEC in May of 1993 in an IEC conducted by Tom Mount.

Did you know that IANTD was first to?

  • IANTD was the First to Teach EANx
  • IANTD was the First to Teach Trimix (multiple levels)
  • IANTD was the First to Teach Open Water Sidemount
  • IANTD was the First to Teach Trimix for Recreational Sport Divers
  • IANTD was the First to Teach In- Water Recompression
  • IANTD was the First to Teach Rebreathers
  • IANTD was the first to Teach Rebreather Cave Diving
  • IANTD was the first to Teach Rebreather Trimix Diving (multiple levels)
  • IANTD was the first to Teach Side Mount Rebreather diving
  • IANTD was the first to Teach Rebreather Wreck Diving

In 1994 Bret Gilliam and Mitch Skaggs teamed up to form TDI. Prior to the formation of TDI, Mitch Skaggs completed the IANTD EANx Instructor program in June of 1992. Mitch completed his IANTD technical diver and trimix diver courses with Tom Mount in June of 1993. In November of 1993 Mitch completed his IANTD technical instructor with Bret Gilliam.

Gary Taylor an IANTD BOA member who had been active in IANTD since 1992 reached the level of instructor in; Advanced EANx-ART, Technical Wreck, Technical Cave, Normoxic and Trimix plus all blending levels. Gary also became an Instructor Trainer in: Advanced EANx, Advanced Recreational Trimix, Normoxic Trimix, Trimix, Introductory Cave, Wreck and all levels of blending and service technician joined Hal Watts at PSA in 2004. PSA under the leadership of Hal and Gary offers all aspects Technical diving. It was at this time they changed the name from Professional Scuba Association to Professional Scuba Association International.

More Technical agencies evolved, and older traditional dive training agencies adopted Technical diver programs many of these were supervised by instructors trained by IANTD. Today PADI, NAUI (The NAUI Training director Terrance Tysall had been a PSA and IANTD instructor) and SSI have endorsed Tek diving.

Summary The world of Technical diving continues to bring new knowledge and skills into the diving population. As we can see the British Cave Diving Group is the oldest cave diving club in existence, the first technical certification programs were:

  1. PSA/PSAI (1962)
  2. NACD for cave diving (1968)
  3. NSS/CDS for cave diving (1971)
  4. IAND /IANTD (1985)
  5. TDI/SDI (1994)

IANTD is proud to have the impact on technical diving it has and continues to have as well as the evolution of all the current agencies and existing agencies endorsing Tek diving. The efforts of all agencies have produced better education, practical training and acceptance of technical diving which collectively has led to safer diving at recreational levels all well.

As you pursue technical and/or cave diving remember two of Tom Mounts philosophies on survival.

“Only you can breathe for you, only you can swim for you, only you can think for you” Tom Mount 1966

“Ki Survival Philosophy Survival’, Knowledge is essential -survival is practical, survival is making the choice to continue and not quitting regardless of the odds, Always remain in life itself not on the problems that exist in the path, it is the quality of life not quantity that defines having lived.” Tom Mount 1999