Cave Diving, Cave Exploration and Cave Mapping in Yucatan, Mexico

Interview with Steve Bogaerts: Part 3 of 3

In February of 2009 my wife and I got pregnant with our first child, which is a wonderful joy as we were trying.  The pregnancy set off a chain of events which resulted in us moving back to the United States.  Well, that move created mass chaos in my life and the fact of the matter is I just didn’t have the bandwidth to maintain the blog.  I was busy moving, buying furniture, going to the doctors and getting my life restarted.  Luckily, some of the insanity is dying down and I can get back to some of my recreational activities like blogging.

Before we get to the third part, I want to thank Steve for being a wonderful instructor and for taking the time to participate in this interview.  His responses were well thought-out and I think will help people when they are considering instructors.  You can find Steve’s new web site at:  So, without further adue….

I asked, “You have a new harness on the market called the Razor, what can you tell us about its development?”

Steve answered, “Well as they say “necessity is the mother of invention”.

I originally designed the Razor Harness for use on Side-mount / No-mount exploration dives in very restricted cave where every piece of extra equipment tries to kill you.

The problem was that in many cases to get to the part of the caves where I was exploring required long penetrations using DPV’s and multiple stages thus increasing my equipment load considerably. But when I got to the area I wanted to explore I needed to be as small and streamlined as possible. I wanted some way to integrate these disparate requirements in one system.

Over the years I have dived just about every Side Mount rig on the market as well as various homemade versions.

All of them worked to a degree but none were ideal.  Like most Side Mount divers I spent a lot of time making modifications to improve the various rigs but was always constrained to a certain extent by the original design and never had a Side Mount harness that I was 100% happy with.

As my exploration dives became more and more challenging, particularly over the last few years, I started to run into the limits of both the equipment and the equipment configuration I was using.

Trying to squeeze myself into ever smaller places was pretty rough on all my gear. I was getting hung up and stuck quite often and in fact in the year of exploration leading up to the connection between Sistema Sac Actun and Sistema Nohoch Nah Chich I managed to destroy 3 different Side Mount rigs. I was running out of equipment to dive in.

I ended up making a simple No Mount harness to go under my Side Mount harness so that when the cave really started to get small I could ditch the comparatively bulky Side Mount rig and carry on No Mount.

The problem was managing all this equipment a long way back in very small cave usually in zero visibility while trying to run a line or survey.  I was spending too much time dressing and undressing while underwater a long way back in the cave and not enough exploring.

Also trying to make sure that I had all the stuff I needed on the right harness at any given moment was a problem and at various times I forgot line arrows or survey slates for example because they were attached to the Side Mount rig I had left behind me in the cave and not my No Mount harness.

Additionally having passed through a section of No Mount cave sometimes it would open back up again and then having a Side Mount harness again would have been an advantage so that I could swim more efficiently.

As well during this period I started exploring from a tiny Cenote called Por One which lay between the Sac and Nohoch systems.

Por One has a nasty no mount entrance where you have to descend down a very tight chimney in the shape of an S.

There was absolutely no way to enter wearing my Side Mount harness, even with both tanks off, so I would begin my dives just in my simple No Mount harness.

Once through the entrance the cave continued in no mount sized passage for quite a distance and often I had to crawl, wriggle and dig my way through to make progress.

Eventually the cave opened up a bit and again a Side Mount harness would have been good to have but there was no way to get my existing Side Mount rig through the entrance and beginning section of the cave.

I needed a simpler more flexible system that fitted my current, more demanding needs.  I decided to start from scratch and design a completely new harness for myself.   It had to function as both a No Mount harness and a Side Mount harness. It had to work with multiple stages and with DPV’s.   The harness also needed to accommodate a totally separate and removable modular buoyancy system.

Ideally the harness also had to meet the following criteria on my rather extensive wish list as well:

  • Small and light so as to be easy to carry on long treks through the jungle.
  • Comfortable to wear and easy to get on and off on the surface.
  • A simple design with no stitching or fancy hardware.
  • Rugged to stand up to the most challenging dives in the most challenging environments where it was going to take a beating.
  • Safe and reliable because my life depended upon its performance.
  • As low profile and streamlined as possible to allow me to fit in the smallest areas possible.
  • Easy to use in very challenging conditions.
  • Easy to adjust.
  • Easy to repair if and when it does get damaged.

Over many hours of brainstorming, lots of test diving and various “Eureka” moments in the middle of the night the Razor Harness finally evolved into what you see today.

There were several prototypes along the way but the final version that I am currently using meets all of my requirements and is by far the best and most flexible Side Mount / No Mount harness I have ever used and has made my exploration dives far more efficient and productive and safer too.

I finally have a harness I am totally 100% happy with and that level of comfort is directly translated into the difficulty level of the dives I can now undertake that I would have hesitated to do before.

After years of experience diving in Side Mount I really thought I knew what I was doing but the last  few years spent experimenting with the Razor Harness have completely redefined my approach to, and philosophy of, Side Mount diving.

It has been like an evolution for me and I feel like I have learned so much and become a much better Side Mount diver along the way and that has been a really enjoyable experience.

I soon realized that if it worked so well for me then the Razor Harness would work just as well for other divers as well.

I started teaching all my Side Mount students in the Razor Harness and noticed a dramatic improvement in their skills, abilities and comfort as well.   Their pace of learning accelerated considerably.

One of the best ways to really understand something is to teach it to someone else.

Teaching other divers to use the Razor Harness really forced me to think deeply about, and refine, all the skills sets and procedures and this has been a really helpful process for me personally as well as a lot of fun.

The current system I teach is the distillation of all that trial and error. That experience refined and streamlined equipment, skill sets and procedures.

Each of the components in the system is designed to fit together seamlessly and work as part of an integrated whole.  The Razor Harness is at the heart of this system and is the foundation of all my “Bogarthian” Side-Mount procedures.

My philosophy is holistic in approach and is designed from the inside out so that as additional layers of equipment are added there is no change in the core equipment, equipment placement, procedures or skill sets.

“Less is More”

The Razor Harness itself is simplicity and elegance personified with only 2 continuous pieces of webbing and 1 closure point.  It is simple, strong, rugged, reliable, low profile and extremely minimalist in design. It fits like a glove and is very comfortable to wear.  The Razor will fit anyone no matter what their physical size or shape and is quick and easy to set up and adjust so that each individual diver gets a custom fit using standardized hardware.  It can be adjusted at several points to ensure the optimal fit for each individual.  All the attachment points such as D rings on the Razor Harness can be adjusted quickly and easily to allow personalized positioning of equipment placement.  Extra attachment points can be added easily if required.  Weight can be added to exactly where you need it on the Razor Harness to optimize trim.

You can easily use any BCD you want with the Razor Harness either wing or jacket style or no BCD at all if using a Drysuit or light tanks and lung volume.

The beauty of not having an integrated BCD is that you can add whatever level of buoyancy is required according to tank size & material, total equipment load, environmental factors, exposure suit type etc.”

I asked, “Are there any other related developments on the way?”

Steve answered, “Yes I am currently working on a modular buoyancy control system specifically to go with the Razor Harness.

When I first started using the Razor Harness I was diving it without any kind of BCD, controlling my buoyancy with just lung volume.

That worked out okay just diving with 2 AL80 Side Mount tanks although at the start of the dive, when the tanks were full, I had to dive at the top of my lung volume and it did not really become comfortable until the tank pressures dropped 500psi and the tanks became a bit lighter.

I really needed a small amount of lift to compensate for the weight of the gas in the tanks at the start of the dive but did not want to add a large and bulky BCD.

In one of my “Eureka” moments I decided to try out a 2l Camelbak hydration bag that I had lying around as a BCD. The 2l volume gave me 4.5lbs of additional lift.

I wrapped the Camelbak horizontally around my lower back over my Razor Harness and held it in place by attaching a bungee cord to one side, running that around my waist and through the front loop of my crotch strap and clipping it off to the other side of the Camelbak with a small snap bolt.

I inflated it orally through the bite on mouthpiece of the drinking tube and dumped air out of it by pinching the mouthpiece between my thumb and forefinger while holding the drinking tube up.  You can also suck the air out of it if you want to really empty it or are in an orientation where dumping will not work.
This is a real advantage when I find myself head down twisted like a pretzel in a restriction!

The concept was so simple and yet it worked fantastically well.  I called it the “BAT Wing” which stands for Buoyancy And Trim Wing.

The BAT Wing is designed to be worn over the Razor Harness. In my opinion sandwiching the BCD between the harness and the body is not ideal for the following reasons:

  • You cannot remove the BCD underwater.
  • The harness restricts the BCD.
  • You need to use a bigger BCD to cope with the reduction of usable volume.
  • The harness may cause air trapping in the BCD making control of buoyancy, trim, gas dumping etc more difficult.
  • Inflating the BCD restricts the harness.
  • When the BCD is inflated it can make the harness uncomfortably tight.
  • If you leave the harness loose enough to allow comfortable BCD inflation the harness will not be as snug and streamlined as it would otherwise.
  • Layering BCD’s for redundancy is more difficult and compounds all of the other issues above.

The most important reason for me to have my BAT Wing over my harness is the ability to easily and quickly remove/replace it underwater while diving if necessary.

Having the buoyancy so low down on my body was the ideal position to help maintain horizontal trim and the fact that it is so close to my center of gravity helped to optimize control when changing orientation in the water.

The BAT Wing is positioned in the small of my lower back and the super low profile meant that I could enter very small areas of the cave with no problem at all.  If needed it was very simple to remove the BAT Wing underwater as it was worn over the Razor Harness just being held in place by a single small bolt snap.

When I got to No Mount areas I could either take it off altogether and leave it behind or wrap it around my butt mounted tank to get it neutral and make towing the tank easier.

When I get to No Mount areas I have 3 options; leave the BAT in place but suck all the air out of it to minimize the profile, take it off altogether and leave it behind or wrap it around my butt mounted tank to get it neutral and make towing the tank easier.

I quickly upgraded to a 3l version that gave me just enough lift (6.6lbs) to dive with a single AL80 stage in addition to the AL80 Side Mount tanks.

I have recently upgraded again to using the MSR Dromedary Hydration Bags instead of the Camelbak’s as they are better made, more rugged and durable and come in a larger range of sizes 2L, 4L, 6L and 10L.

The beauty of not having an integrated BCD is that you can add whatever level of buoyancy is required according to tank size & material, total equipment load, environmental factors, exposure suit type etc.

I am currently using a 2l for No Mount dives, a 4L for Side Mount single stage dives and a 6L for Side Mount multi stage dives.

In addition it is very easy to layer the bags one on top of another for redundancy.

While this system is very, very good I have a few ideas that I hope will improve it further.

At the moment I am in the process of developing a commercially viable modular BC system along the same principles specifically for the Razor Harness and hope to have something available very soon.”


1 Dave { 07.16.09 at 7:05 am }

Nice interview and great photos…look forward to seeing the modular BC’s. Are those 0-rings on the waist belt and are the 1″ d-rings welded to the serrated belt slides? The bungee appears to be one continuous loop…does this cause a problem if you remove only 1 tank?

2 Jason { 07.16.09 at 8:30 am }

Very good read, nice job Hans.
Looking forward to the definite BAT Wing!!!

3 Fred { 08.13.09 at 3:48 am }

Unfortunately in my contry (Brazil) we can’t find 4 L, 6L and 10L camel baks we have to import !!!!
So we have to use a light wing BCD, u guys can help me out with some ideas.