Seeing Red at 40 Meters (130 Feet)

One of my favorite dives was the last dive of my Deep Diving course. There wasn’t a wall at the dive site, so we swam out from the beach and headed straight out until we reached a depth of 40 meters.

Then I saw the color red.

As you can see above, this is what the color red looks like at 40 meters with a flashlight.

However, I did not have a flashlight with me.

Therefore, as you can see in the unlit image above, there is no way I saw the color red at a depth of 40 meters. That wavelength of light is absorbed by the water. Notwithstanding the impossibility of my observation, I nonetheless saw the color red at 40 meters.

I didn’t bring a camera on that dive, because I knew the available cameras would shut off at that depth. I also thought to show my instructor, but she was narced up and drifting away from me. I had no way to get her attention without sprinting over to her, which would’ve consumed alot of gas at that depth.

When we surfaced later, the first thing I told my instructor was that I had been so narced up I saw the color red at 40 meters. We both really enjoyed that dive actually. I then took the written test and completed my Deep Diving specialty.

Will Work For Air

I saw this tweeted; it was presumably meant as a joke. I retweeted it because I actually mean it!

For more great original content like this image, visit scubaluis.com, like on Facebook, follow on Twitter and Instagram, and read the reviews on TripAdvisor.

All of my certifications, specialties, recognitions, and dives to date have been heavily discounted or even free. I wrote content for a website and for several social media platforms, and I also took photos and videos.

I’m a marketing professional with a complete set of tools. I’ve done everything from direct mail to media relations to print/TV/radio advertising to interviews to speeches to, of course, websites and social media.

My alter ego is as a developer. I began, as you may imagine, developing databases and systems for marketing companies. My clients have ranged from Fortune 100 companies down to local non-profit organizations.

So, if you have a dive center in my area, or where I’ll be moving next year, maybe we can make a deal?

Deep Diving!

I have completed my Deep Diving specialty, and it is the most fun course I have taken to date!

My final dive of 3 was a shore dive to 40 meters. I didn’t bring a camera, because I know it shuts off at that depth. However, I did bring a mesh bag and we removed quite a bit of debris from Shangri-la Marine Sanctuary off Mactan Island, Cebu, Philippines.

In fact, my instructor, who was a different instructor because the instructor who started the course was unavailable that day, was amazed by my ability to find debris in such a relatively clean dive site. She said that everytime she looked around to make sure I was still with her, I was always picking up a new piece of debris.

Ironically, deep diving is fun even though there is relatively little to see down there. The corals stop around 30 meters or so, so our scenery becomes much more sandy.

However, there are little pockets of life scattered around. I think that is part of what keeps it interesting: wondering how and why these little pockets of life exist at a depth that seems relatively inhospitable compared to real estate that is only a short swim away.

Then, of course, there is narcosis, a side effect of inhaling nitrogen at depth. I have not felt narced up (comparable to being drunk), however my behavior has indicated otherwise to my instructors. Maybe that’s the hidden reason behind why I have enjoyed deep diving so much?

Freefalling Underwater

I highly recommend taking a deep diving course.

You descend the first few meters like you normally do, making sure you can equalize the pressure in your ears. Then… the brakes come off!

There is no speed limit on the descent, so you freefall faster and faster just like in skydiving. Instead of pulling a parachute, you inflate your Buoyancy Compensator Device (BCD) to achieve neutral buoyancy at your target depth. In this case, our target was 40 meters, and the bottom of the wall at Kontiki off Mactan Island, Cebu, Philippines, was conveniently almost exactly 40 meters.

This must be why I see so many photos of technical divers looking like skydivers. That does seem to be the natural position you take as you watch your depth on your dive computer.

If all goes well, you get narced up (nitrogen narcosis) on the descent. I don’t think I got narced up, but my instructor disagrees.

He made the point that I didn’t achieve neutral buoyancy at the bottom. I conceded that I was aware of that, but there were too many photos to take and too much debris to retrieve before reaching our No Decompression Limit (NDL). I think I would have the same buoyancy critique at any depth with that much going on in so little time.

Anyway, we’ll do another dive to 40 meters. I won’t need to take the camera, so that’ll be 1 less distraction. Plus, the camera shut itself off at depth anyway, and wouldn’t power back up until we were ascending.

I’m looking forward to my next jump! There is little sightseeing to do down there so far, but you can stop and smell the proverbial roses on the way back up.

SCUBA & Bodybuilding?

The other day my wife asked me if I am getting bigger.

At first, I brushed it off. I haven’t had time to go to the gym and I haven’t been working out much at home, so I really can’t be getting bigger.

On the hand, if anyone were to notice such a thing, it would be my wife. 

So that got me thinking. What is the relationship between scuba diving and bodybuilding? We learn in scuba diving that nitrogen retention is very bad, but we learn when bodybuilding that nitrogen retention is very good.

A quick search online suggested the two are unrelated. However, everything I found was about the safety of nitrogen-retaining bodybuilding supplements and scuba diving. There was nothing about scuba-related nitrogen retention and its effects on bodybuilding, nor was there any evidence that any of these forum commenters have any idea what they are posting about.

In other words, I found nothing at all about scuba-related nitrogen retention and bodybuilding. All I have is one unscientific comment from my wife, so my quest for answers continues….

1st “Fun” Dive

My first “fun” dive put me in the hospital!

For those who don’t know, there are two types of dives. There are training dives, which count toward certifications, and “fun” dives, which are not taken as part of courses.

Dive #5 was my first “fun” dive. I had just completed my SSI Open Water Diver certification, so this dive was not working toward anything in particular. It could have been, but we didn’t have time between dives.

To recap my day, it started with an academic session about Enriched Air Nitrox. We then dove nitrox at Baring, Olango Island. Upon returning to our dive center, we heard about a boat leaving in the early afternoon. I would need to be a certified Open Water Diver to go. So, I took the written test and passed. The dive center manager made it official, and we began to prepare for our next dive.

You may have noticed that I did not mention having lunch. Although I did not feel hungry, that was probably bad. Also, we brought atmospheric gas for this dive.

We boarded a boat destined for Marigondon Cave off Mactan Island, Cebu. We did not intend to enter. Our goal was to descend enough to see it, and then drift along the wall. I just wanted one good photo of the entrance.

Upon arrival, we noticed a strong current. We descended and tried to swim to the cave entrance. I tried to do a controlled descent, like we have always previously done. My dive buddy made it over to the entrance, but I couldn’t get there. My finning technique must not be good enough. I exhausted myself trying.

My dive buddy motioned me to descend more quickly and then try to swim over to the entrance. Unfortunately, I was struggling to descend, and was already breathing heavily.

I followed my dive buddy, and we headed with the current to the wall. We descended down the wall and started to drift.

My dive buddy gave me a choice: go back to the entrance or drift away from it. I chose to drift. I was exhausted.

I’ve been doing some research. I did not want to be a panicked diver. I tried to slow my breathing. 

Unfortunately, a demand regulator requires effort to breathe. I could not slow my breathing. I think I was hyperventilating for about 35 minutes. I don’t remember how long our dive was.

I also don’t remember our maximum depth; we had already done 18 meters, so I assume I was hyperventilating 78.9% nitrogen at 18 meters.

As soon as we surfaced I started dry-heaving; I heard my dive buddy say, “that’s not good.”

My dive buddy and the boat crew helped me aboard the boat. While on the boat, my nose bled, I vomited, I defecated (in the onboard toilet), and was administered oxygen. The closest comparison I could make is that I felt like I had been to a party and had one shot too many.

I was assisted back to the dive center. Over the next few hours, I vomited more, defecated more, and was administered oxygen again. I was eventually able to take a hot shower, which is when I noticed my white feet slowly regain their color.

A few hours later I was escorted to a hospital. Everyone suspected vicious seasickness, but I’ve never been seasick that seriously nor that long.

I felt more comfortable going to a hospital than going home. I was discharged around 1:30 AM. They were also treating me for seasickness.

I went home, and woke up feeling hungover in the morning. I was “seasick” for about 24 hours. In fact, I still feel less than 100% almost two full days later.

Either way: lessons learned. No more skipping lunch. If I miss a boat, the house reef is fine to pick up trash and take close-up photos. Also, no more atmospheric air. If I needed pure oxygen twice, it seems to me that having enriched air at 0-18 meters might have been helpful.

Enriched Air Nitrox

I needed one more dive to earn my SSI Open Water Diver certification. My instructor decided to do it on nitrox!


What is nitrox? The short answer is that it is any mixture of nitrogen and oxygen. We are all breathing nitrox right now! However, it is generally short for Enriched Air Nitrox, which has a larger percentage of oxygen and a lower percentage of nitrogen.


Why is that important? Oversimplified, excess nitrogen leaks into your bloodstream and can cause an assortment of health-related issues. By reducing the percentage of nitrogen and increasing the percentage of oxygen, you lower your risk of nitrogen narcosis and decompression sickness. You extend the time you can spend at your maximum depth, and reduce or eliminate your need for decompression while ascending.


So, we started off with an academic session. It’s mostly math. And it went by fairly quickly because I had already studied quite a bit of it in anticipation. The interesting thing is, contrary to previously stated benefits, that your maximum depth rises in direct proportion to your oxygen content. In other words, when you elevate your oxygen percentage you also elevate your maximum depth, meaning you cannot dive as deep. If you want to dive deeper than your oxygen percentage will allow, you need to decrease your oxygen percentage. That, then, increases your nitrogen percentage, reduces your bottom time, reduces your no-decompression limit (NDL), and so forth. You have to find the correct balance for your dive.



Thanks to a YouTube video by Lake Hickory Scuba (on Twitter as @lhscuba) I already knew the Magic Circle. That both makes the math easier and speeds up the class quite a bit. Spoiler alert: it is even easier to do in meters.


We then proceeded to select our nitrox scuba tanks. The first thing you do is test the oxygen percentage yourself. You always test it yourself. We calibrated the testing device on atmospheric air first, since we know the oxygen percentage is 20.9%. After testing my nitrox canister, I used the Magic Circle to label my canister. My oxygen percentage was much higher than my instructor’s, but we were not planning a dive below 18 meters anyway.


We then got ready and jumped on a boat to Baring, Olango Island. But, that is for another blog post.

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