Underwater Cave Diving


Recently everyone breathed a sigh of relief as the world watched a daring cave rescue. Fair to say that most people envisioned themselves underwater cave diving 2.5 miles back through dark murky tunnels hoping to see the light of day once again. For some people, just the thought of underwater cave diving can raise blood pressure, heart rate, and stir up feelings of claustrophobia. For others, cavern and cave diving is a recreation fueled by an insatiable desire to go around the next corner of the underwater labyrinth, to go deeper, further, explore, repeat. To quote the title of a book written by one of the early cave pioneers, Martyn Farr, “The Darkness Beckons”. The purpose of this blog is to shine an underwater cave light, preferably with 2 LED driven 24W bulbs producing over 3500 lumens @ 6500 Kelvin on the subject of recreational cave diving. As a cave diving facility, we hope to enlighten the reader as to why anyone would want to place themselves in an overhead environment with all the room in the ocean.


North Central Florida and the Yucatan Peninsula of Mexico are two of the most popular places in the world for underwater cave diving. Focusing on the popular cave systems here in Florida, most are large and extensive soft limestone rock tunnels that form our very shallow aquifer and exit at one of the many popular springs.  Ginnie Springs is just outside of Gainesville, Florida has over 30,000 feet of underwater guidelines. The mountain cave in Thailand was a “sump” which is normally more difficult and dangerous due to low visibility muddy waters, excessive flood currents and dangerous dry cave terrain. This type of cave diving will not be addressed in this blog. There are miles of large, clear, beautiful 72-degree underwater cave systems that are open to the qualified public, and divers in training. There are also thousands of tributaries and connecting tunnels that can be very tight, silty and dangerous as we saw in Thailand. These tunnels are sometimes utilized by advanced underwater cave divers to access other rooms and ongoing cave. As an ENTRY LEVEL cave diver, with the proper training and equipment, you will be directed to stay away from difficult cave configurations, keep to the large main rooms, on the main line, diving within your training limits; so let’s begin with the limits.


Basic open water scuba diving certification is the obvious prerequisite, advanced open water training recommended, as well as at least 50 dives. An occasional diver should not jump into a cave class but might want to consider a two-day cavern. As a cavern diver, the student never leaves the natural daylight zone. Manatee Springs State Park in Chiefland Florida is a good example. A “Karst Window” is an opening to a cave from a naturally lit spring. You can enter the “cave” without leaving the daylight zone, and partially view the upstream and downstream tunnels. A Cavern class is very good for tweaking your buoyancy control, dive planning, task loading, and overall awareness skills. If you are an experienced diver, your blood type consists of higher than normal levels of adrenaline, you have been poking your head in every dark hole since you were a kid, and you have lots of money to burn on technical dive training and equipment, (this is not a poor man’s sport), then read on.


Find an experienced instructor. Bill “Bird” Oestreich, owner of Bird’s Underwater Dive Center has been teaching for over 25 years, as well as many of our professional colleagues in the tech industry. Research your potential instructor, teachers improve with each student and diving scenario.  The reader should know that there are designated areas within the cave systems dedicated to underwater cave diving drills and training exercises so as to minimize damage to the systems and allow familiarity to the instructors. Students do not explore, they experience the environment and learn safety and emergency procedures. There are several different levels of training such as Cavern, Intro to Cave, Apprentice Cave and Full Cave Diving. The names change with different agencies, but it remains a step by step training procedure. The NSS/CDS and TDI-SDI are recommended tech diving agencies.


There are five basic rules for diving in an overhead environment. Keep in mind that most of the popular, public caves in Florida and Mexico are 100 feet or less in depth. Deep diving is far more dangerous and has its own set of rules that are not mentioned in the rules below. Advanced cave training, deep cave, technical nitrox, tri-mix, rebreather and other specialized technical diving requires continued and specialized education. Cave diving classes focus on safety, emergency procedures, dive planning, air consumption, laying lines, equipment configuration, decompression, buddy communications, and many other skills that focus on safety first so that each dive can be enjoyed within the physical, mental, and experimental limitations of each individual.
Five basic rules for cave diving safety that must be followed by every diver are:
1. Always use a continuous guideline to the surface.
2. Save two-thirds of the total air supply for returning to the surface.
3. Carry at least three lights during the dive.
4. Limit dive depth to that appropriate for the gas being breathed
5. Be well trained in cave diving and mentally prepared for the dive.
These five rules are based on an evaluation of the cave diving fatalities mentioned above, called “accident analysis,” and have been shown to be effective in preventing most accidents in underwater caves (Zumrick et al. 1988) https://http://www.bestpub.com/blog/entry/cave-diving-safety.html

This blog is not meant to entice anyone into the sport of cave diving, it is definitely not for everyone, to lend an understanding as to why there are people drawn to this sport and training options for those who might consider it. Let us demystify the underwater caves and debunk the mindset that cave divers have a death wish. If a picture paints a thousand words, consider the beauty in photos taken by Jill Heinerth, Becky Kagen, Mark Long, and the late Wes Skiles, talented photographers in the field of cave diving. Benefits of include the ability to see a very beautiful part of our planet that even the most daring explorers have never seen. More miles have been traveled in outer space than underwater. If you are not certified to scuba dive in open water we highly recommend that you consider a basic class, it is fun for all ages and detailed in previous blogs, as well as the SCUBA DIVING section of our website.  Safe Diving.

A Blueprint for Survival by Sheck Exley

The Darkness Beckons by Martyn Farr