I Went Scuba Diving

2026-09-03T19:30:00.000Z

My partner has been scuba certified since the age of twelve.^[1] I have long enjoyed hearing animated stories of the cool sights to be seen, the majesty of coral reefs, and the safety and care that goes into such an ecological sport. In 2022, as a birthday/holiday present, my family bought a special phone case for my partner to go diving with so that we could see pictures and videos of the results.^[2] Getting to see what was down there has definitely made me appreciate the activity more than hearing about it ever did. It's a lot of work to edit any of the photos to balance for the blueness^[3] and low contrast of the ocean, which is why these images are just presented as is. Despite all of the stories and pictures and videos I had seen and heard, for years, I had maintained my stance that I was uninterested in ever going scuba diving, myself.^[4]

This week, I went scuba diving for the first time, and I loved it. My partner and my mother-in-law^[5] and I all went to Cozumel, Mexico to dive along the Great Mayan Reef.^[6] This is the second largest reef in the world after the Great Barrier Reef, and it stretches on for 625 miles^[7]. The Cozumel portion of the reef tends to have huge underwater cliffs lined with coral. This makes for scenery that is a combination of seeing novel marine life and appreciating a sort of architectural geology.

For a person who has never gone scuba diving before, there are programs that certain dive shops offer like "discover scuba" where you can have a guide teach you what you need to safely dive before taking you on a roughly 45 minute underwater tour to immediately test your skills. During that dive, you'll generally stay at or above 30ft deep, which means that if anything goes wrong and you and your guide can't find a fix for it underwater, you're safe to swim directly to the surface, and potentially even end the dive early. This appealed to me as a safe subset of scuba diving: I'd never have to worry about decompression sickness at all, and I would be able to go deeper and spend a longer time underwater than I ever did snorkeling. Going in, I thought that scuba diving required you to be 1. great at swimming, 2. obsessed with being underwater, 3. clean-shaven. Each of those items helps but is not necessary.

You don't need to be great at swimming

I currently cannot easily swim the length of an olympic swimming pool. I can tread water, and I can swim for survival by alternating floating and the backstroke, but that's about it. With flippers, I can go a lot farther a lot faster, but my technique for most swimming styles is lacking. Despite that, I had no trouble swimming while scuba diving.

The primary method of movement while scuba diving is the same as a fish: a swim bladder. Your equipment includes a Buoyancy Control Device (BCD) that can fill up with air from your tank and has pockets for additional weights. By balancing the buoyant force of the air in your BCD against the gravitational force of the weights, you can achieve perfect buoyancy, meaning that you will neither sink nor float. However, you need to breathe^[8], so you must inhale or you'll eventually be at risk of hypoxia. But, by inhaling through your regulator, your lungs expand with gas that makes you more buoyant, and as you exhale, your lungs shrink back down and you become less buoyant. Because inhaling and exhaling take some time, you wind up being able to control your buoyancy through the regulation of your own breath.^[9] Recall that there's lower pressure at higher altitudes, even in water, so there is some real danger in holding your breath: your lungs are only supposed to fluctuate between a certain range of sizes, and the extra pressure from changes in depth could cause you permanent damage. For this reason, the number 1 rule of scuba diving is to "keep breathing."

One of the other main rules of scuba is to clear your ears regularly. As the water pressure around you increases or decreases, it can be very similar to a plane takeoff or landing in terms of your ears' need to "pop" so that your inner-ear stays neutrally pressured. Failure to neutralize this pressure tends to hurt after a bit, and if ignored too long can cause permanent hearing damage! If I was a physics teacher, I'd focus on these problems as a more important part of scuba diving to know about than decompression sickness, I think.

You don't need to be obsessed with being underwater

I have generally enjoyed going in the water since I was a kid. I never thought of myself as a mermaid or anything, but I liked the challenge of diving deep to get stuff off the bottom of the pool. I tried snorkeling when I was in middle school, and I liked that too. It was tough to breathe and I always felt like I had more I wanted see before we had to head home. In college and afterwards, I entered a sort of negative feedback loop where I'd go somewhere that had water and hang out but never actually go in, which made me not want to go in because people knew me as someone who didn't really go in the water. I've grown more and more distant from swimming to the point where I could probably count on one hand the number of times I've actually swam in a pool or ocean in the last decade or so.

That all being said, you may have noticed if you've been reading this blog that I enjoy wildlife quite a bit. Scuba diving to me is a lot less about being able to achieve some dream of swimming in the same manner as a fish. Far more important is the way that scuba diving emulates a hike or bird-watching, just underwater. Yes, many of the fish on a reef at first may look like the ones in your Dentist's tropical salt-water tank. But I'm someone who finds meaning in being able to distinguish a house sparrow from a house finch or a crow from a raven in my local neighborhood, so I am just as likely to have fun telling a parrotfish from a triggerfish or a boxfish from a cowfish out here.

And if I know which houses' eaves a corvid may like to sit and caw from back home, I can also appreciate the shapes and structures of reef ledges that give spots for eels, fish, and crustaceans to rest.

Ed Yong^[10] said in an episode of Okay But Birds that:

I think one of the joys of birding is that there is this glorious, virtuous cycle between how much you look and how much you see. And the more you look, the more you see. And the more you see, the more inclined you are to spend your time looking. And that's what happened to me.

I find the same holds true for scuba diving in a couple of ways. Even after looking at a dozen coral reefs that seemed to mostly have the same sorts of fish in and around them, closer inspection of any one reef or piece of coral could reveal something camouflaged like the Caribbean reef crab,

something safely nestled between arms of coral like the trumpetfish,

or something much smaller like the arrow crab, for instance.

And as you leave one coral reef and come upon the next, there also tend to be opportunities to look up and further away, where you might realize that you're in the presence of an exciting and much bigger organism.

It should be noted that despite plenty of movies, TV, and music insisting that animals like sharks and barracudas are dangerous, they are generally harmless if left undisturbed. Reef sharks are particularly docile as long as you stay out of their space, and barracudas tend to only go after small shiny fish. If you're wearing small shiny jewelry, that might be a problem, but even then, the chances of your jewelry glinting in exactly the wrong way to fool a barracuda and have it think it can get that "food" while you, a much larger "fish" are swimming right nearby, are low. As with all wildlife appreciation, you should keep a respectful distance and keep your hands to yourself.

You don't need to be clean-shaven

When I climbed onto the boat, my dive instructor began running through the high-level overview of how scuba works and the safety measures we would be taking. He had a large beard and long hair, so I asked about whether his facial hair ever gets in the way of creating a good seal with the dive mask. He said that there's usually a slightly worse seal because of his moustache, but that there was no problem besides a little bit of water under the nose from some initial leakage at the surface. He explained that while diving, you generally want to exhale a little bit out of your nose from time to time to make sure tha air pressure in the mask balances out the water pressure outside the mask, and that positive air pressure tends to keep the slightly worse seal on the philtrum^[11] from getting much water into your mask. Apparently, not balancing the pressure during descent into the depths can lead to facial barotrauma, so it's better to just exhale a little through your nose every so often and do the rest out the mouth!

Other things I learned

Communication

Because the regulator is in your mouth and comprehending spoken words underwater is already pretty fraught, communication during scuba diving is limited. There are several common hand signals that recreational divers use, many of which I learned^[12]. I think it's pretty fun to be in a place where viewing wildlife is a primary goal, and when you see something exciting, you need to be able to tell other people where to look and what to look for without using words. And when they see it, it seems common to either point or mirror the gesture back to confirm. Some divers will bring a small noisemaker that they can briefly use to get divers' attention from further away before communicating what they saw.

I wish that there was more of this "mostly silent communication" in birding. I sometimes find the discussion about "what bird do you think that was" or "wow, isn't that so cool" or "which bird song were you referring to" to get in the way of focusing on the wildlife itself. The silent acknowledgement of things underwater leaves something to be desired on land.

It's funny timing to have a new activity in my life that features communicating without sound, given how much I've been playing Big Walk this summer with friends. There are plenty of parts in that game where not being able to hear the other people you're trying to communicate with is a core feature of the design, and I've greatly enjoyed it.^[13] There are even arm signals you can do in the game, even if they're not that expressive. I'd love to see an online cooperative exploration game in the same vein as Peak or Big Walk attempt to make the communication of cool stuff you see be the goal of the hand/arm signaling.^[14]

Camouflage to humans

I was fortunate enough to see both little yellow stingrays and larger southern stingrays while diving. The yellow stingrays were better at camouflaging themselves against the sand and grass, but it was very common to see each stingray with another fish hitching a ride right above it to try to gobble up any loose bits from the messy way stingrays eat their food. This meant that there were grassy sea floors where you would see a couple of stationary brown-colored bar jacks,^[15] until you realized that each of those floating fish was actually giving away the position of a yellow stingray below it.

This particular southern stingray had a smooth trunkfish above it, which was a rare exception to the bar jacks we otherwise saw.

Scuba diving is expensive

Even ignoring the costs of getting there,^[16] scuba diving is prohibitively expensive for most people. I think that's a shame, and in an ideal world, reefs and other interesting places to go underwater would be protected, subsidized parks, just like their above-ground counterparts. Scuba diving costs should be comparable to the costs of backpacking. Generally, it should be cheaper to go outside to see wildlife than just about any other recreational activity, in my opinion.

I hope that I can get scuba certified and keep diving for many years in the future. I know there are live-aboards that allow you to ammortize the travel and shelter costs quite a bit, even though they're often more remote. My partner and I are extremely privileged to have the freedom to travel that we do.

I like swimming with turtles

I have liked turtles for the vast majority of my life. They were something I'd get to see at aquariums or maybe in a fountain at a park. Occasionally they would be featured on some documentary about how fragile the baby turtles are or how corporate irresponsibility was leading to plastic hurting or killing them. I've had friends who owned pet turtles. All of these are sort of admiring or caring for turtles from afar or outside of their natural habitat.

Going into scuba diving this week, the one animal I wanted to see more than any other was a sea turtle. Obviously I'd be excited to see sharks or eels or an octopus or something, but my big hope was for getting the chance to swim in the same water as a turtle and sort of occupy the same approximate space.

And I did, and it was great.

Prior to the age of 15, you can get a Junior Open Water Certification. At 15, you're eligible for Open Water Certification.^[17] ↩︎
All of the included photos were taken by one of us from a phone in that case. I'm not trying to advertise for this specific case as much as I want to make the methods reproducible. ↩︎
Or maybe I should say "lack of redness," since there's very little emitting any extra light down there. ↩︎
A big part of this was from completing a classic chemistry problem from high school and college about "The Bends" and a bunch of misinformed opinions about the safety precautions dive groups take in choosing where and when to go, as well as misinformed opinions about what a person scuba diving needs to do relative to this biological constraint. ↩︎
Just the one law and one implied blood. My MIL has been my partner's dive buddy for many years, and this time I was convinced to come along and try for a day, while otherwise just taking a relaxing week off from work as the two of them went diving. ↩︎
Going scuba diving for the first time in Cozumel has absolutely spoiled my expectations for what a good dive is like. The water is some of the clearest in the world, the reefs are huge and have plenty of biodiversity, the water is usually just as warm of a temperature as the air, and the weather tends to be very agreeable, even during the stormy season right now. The only usual downside is fast currents, sometimes as much as 4-5 knots underwater. ↩︎
Approximately the distance as the crow flies from New York City to Charleston, North Carolina. ↩︎
This is close enough to true to just accept as a precondition for scuba diving. The record depth for Constant Weight Apnea (free-diving) is 136 meters in 4 minutes 37 seconds. Most scuba divers would need to breathe before that point. ↩︎
The intuition required to know how much to inhale or exhale is definitely a learned skill. I think there could be an interesting sort of Flappy Bird clone where your input is tied to your breathing, but maybe just mapping breathe-in to one button and breathe-out to tapping a second button could wind up with a close-enough approximation to get the gist? ↩︎
A journalist whose work and talks I've greatly admired for a while ↩︎
Your philtrum is the skin above your upper lip and below the septum of your nose. ↩︎
My favorite one was squid, which was basically the same gesture with one hand that you might do if you were a bored teen and wanted to make and overly complex handshake after doing a "pound it" gesture. We did see two squid go by, which is the only reason I learned what the gesture was. ↩︎
I've seen several of my gaming friends enjoying it ok, but where I think the game really shines is in the crowd of people who have not gotten used to twin-stick movement yet. The fact that it has no game overs makes it a fantastically approachable game. If you're thinking about getting it but don't know who to play with, I highly recommend finding your friend or family member who has expressed some vague interest in games before but was afraid or anxious of losing or being stressed out. This is a game you could play with your parents or your kids or both. ↩︎
Journey may have gotten the closest so far to this, in that there was online multiplayer coop without talking, but most of the things to point out were not wildlife, and the expressivity of the communication options were lacking by today's standards. Portal 2 back in 2011 gave many options for pinging with puzzle-specific contexts like "countdown from 3" or "stand on that button", but it wasn't until Apex Legends in 2019 that pinging as an expected tool in multiplayer games really became the form that it is today. ↩︎
You can read more about the association between the bar jack and the southern stingray ↩︎
Transportation costs to get to the rough area you want to dive, hotel costs, and then the cost of the actual dive itself, which is ignoring the cost for taking time off from work. Scuba is on par with skiing in terms of unaffordable activities. ↩︎
Open water certification is generally what you need to go regular scuba diving. See ISO-24801 for more information about the international regulations of scuba diving. ↩︎

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