A Brief History of The Cave Diving Line Arrow – The Forrest Wilson Story

Here at ProTec Dive Centers we are passionate about cave diving! And, we are massive geeks about cave diving history and technology. Recently, I sat in on Cristian Toro’s lesson on cave diving navigation. We got to talking about the history of cave markers and the origin of line arrows. Following our discussion, Patrick Widmann, Resident Cave Explorer and Director of Training, contacted Forrest Wilson (the inventor of the line arrow as we know it), to learn the story of the arrow’s development. The following is summary of the personal correspondence between Patrick Widmann and Forrest Wilson.

Cave Diver Installing Line Arrow - Credit Global Dive Guide

Finding The Way Out With Arrows

The use of arrows to indicate the direction of the the exit originated in dry caving. Early cavers used smoke from torches or carbide lights to leave smoke arrows on the cave walls.

The Evolution From Dry Caving to Cave Diving

When the cave diving pioneers started cave diving in Florida, nobody left permanent lines in underwater caves, therefore there was no need for markers. The divers just reeled in the line as they left the cave. According to Wilson, John Harper was the first to leave line in caves, but he didn’t think of line markers. Other cave divers used things like clothespins, or the outrigger clips used by fishermen, especially once T’s and complex navigation became popular. Following a cave diving accident in Florida most of the T’s were with gaps, requiring jump reels.

In 1976, the death of a lost cave diver at Peacock Springs in Florida prompted the development of a marking system. Lewis Holzendorf invented the idea of using triangles made of duct tape folded on the line as “arrows” thus they were known as ‘dorf’ markers. Dorf markers suffered two major flaws: they folded up or deteriorated over time. However, it is possible to find the remains of scrappy ‘Dorf’ arrows on the lines in caves such as Xunan Ha, a cave re-explored and mapped by Hans Kaspersetz and others.

Innovation and Durability of Cave Diving Line Arrows

At an early National Speleological Society-Cave Diving Section Workshop, Sheck Exley asked Wilson to lead a discussion. The workshop was on the development of durable line arrows. Wilson’s idea was to use a thin plastic triangle that could be folded on the line, and snapped closed, much like a Dorf marker. One of Exley’s requirements was to keep the name of the marker the Dorf marker, since Lewis was a good friend of his. Original Cave Diving Line Arrow Illustration from NSS-CDS WorkshopDuring the workshop Roger Werner drew a triangle on the blackboard with slots, but they had no holes or notches and would never stay on the line.

Wilson tried several things, including three slots, ending in holes. They stayed on a line fairly well, but took too much time to install. Next he tried two slots with holes centered on the slots, but they didn’t stay on the line very well. Accidentally, Wilson drilled the holes offset from the slots, and those did stay on the line.

Photo of an original cave diving line arrow prototype with 3 slots and offset drilling

I’ll Never Be Able to Sell Another Line Arrow!

Forrest Wilson hand made 100 arrows and took them to the Branford, FL dive center to be sold. When Wilson brought a second batch of line arrows to the shop, the shop owner told Wilson they would never be able to sell the arrows. The shop owner said,

“There are only 10 caves, and if you put 10 arrows in each cave that would be 100 arrows, and he wouldn’t ever be able to sell another line arrow.”

All of the hand made arrows Wilson created were sold. One of Wilson’s students owned a cave rope manufacturing company.  He requested 1 “perfect” arrow to use for an injection mold. Eventually, Dive Rite bought the mold from him. The rest, as they say, is history.

January 6, 2018   No Comments

A Cave Instructor’s Journey

Sidemount Cave Diving in Halocline, Playa del Carmen, Mexico

Everyone’s journey is different, this is mine to date.

I started diving at the age of 23. Knowing what I know now, it was later in life than I would have liked but at least I did! I tried it, I loved it, I worked hard and sold everything in order to move to a tropical island to pursue my new love of diving.

Soon after I started diving, my interest swung toward wrecks, “swim throughs’, and anything technical. I proceeded to begin my Divemaster course which included diving at least twice a day, nearly every day for the next 4 years on the island.

Thousands of divers came and went, of all levels of experience and backgrounds. Like anything you have a passion for, your awareness grows and influences change.

For almost a year, I assisted multiple different courses as a Divemaster candidate. This allowed me to become confident enough in my skills and knowledge to move to the next step – Open Water Scuba Instructor.

Some say it is a fast process. I agree, however due to this process you are able to fully immerse yourself in activities where you can rapidly progress your skills. You learn the importance of being aware of your own abilities, how to critique yourself, and to know the areas in which you need to improve.

During this time, I completed many technical courses which included becoming a Full Cave Diver. This was the course that piqued my interest in proficiency, overall diving skills, and solution thinking. I absolutely love diving in the ocean and miss the marine life after some time in caves. That being said, my curiosity to learn new skills, enhance my knowledge and to see ‘history frozen in time’ are all reasons that have brought me to the Yucatan Peninsula, Mexico 5 years later.

Over 7 years have passed since I took my first breath under water.

I have been lucky enough to have dived and worked in many places around the world. I have dived caves in many places that have enabled me to build my cave experience, knowledge, skills and have now lead to my eventual goal of becoming a cave instructor.

For me, it is most important to dive and teach with an open mind built upon previous experiences.

I have now commenced my journey to becoming a Cave Instructor, 2 years diving almost everyday in the beautiful, delicate cenotes of the Yucatan, Mexico.

For me, it is important to dive and teach with an open mind and to build upon previous experiences. I have commenced my journey to becoming a Cave Instructor by diving two years everyday in the beautiful and delicate cenotes of the Yucatan Peninsula.

Cave Diving Training Land Drills, Playa del Carmen, Mexico

As importantly, I am able to dive, assist, and surround myself with the best in the world. These influential cave divers who are highly skilled, experienced and best of all humble.

This pushed me every dive to be aware of my abilities, critique my own diving techniques and to acknowledge where I need to improve.

There is no way to move through this process rapidly and safely. With time comes good and bad experiences that I will learn from and which will then be passed down to my future cave students – that is what I look for in my Instructors and mentors.

In due time the next phase will be examinations and ‘A Cave Instructor Journey – Part Two’.

This amazing journey of practise and development continues.

Tamara May – Cave Guide and Instructor at ProTec Dive Centers

September 6, 2017   No Comments