How Many Divers Are There?

It's a simple question: how many certified scuba divers are actually out there? Unfortunately the answer is not so simple, for several reasons.

Abacus

  • Organizations don't share data. Certification agencies tend to not release data about how many divers they certify. One exception is PADI, although they have been accused of inflating their numbers in the past. Without reliable numbers, it's much harder to get a good estimate.
  • Lack of trends. For the few years that data is available, we can't extract any meaningful trends. For instance, we can't say anything as strong as "for 20 years diver certification has grown by 10% each year." The numbers seem too erratic to extrapolate.
  • Error. The error also can be high, due to things like divers getting certifications from multiple agencies.

Despite these drawbacks, there have been several attempts at nailing down a number.

The best numbers we have are from DEMA, the Diving Equipment and Marketing Association. It is in their interests to know how many divers, and thus potential customers, are out there.

DEMA has data from three agencies (PADI, SDI, and SSI) for new diver certifications between the year 2000 and 2008, seen below.
Total number of certified divers by year

Using some fancy mathematics, we can see that in those 9 years, from those three agencies, 1,449,751 were certified. Unfortunately, as said before, these numbers are too erratic to usefully extrapolate. Also, we're missing numbers from NAUI, the second largest certification agency.

From here, it's time to start guessing. PADI provides some certification statistics that may help us guess intelligently.

The first thing you'll notice is that PADI's numbers are much larger than the total numbers from DEMA. That's because PADI is counting total certifications, not entry-level certifications. I assume this includes things like specialties, which inflate the numbers for the past few years up to almost a million certifications per year.

Let's adjust our 2000-2008 numbers to account for NAUI (and other organizations). I think it's safe to assume that doing so will inflate the number up to around 2,000,000 certifications.

Fortunately, we only need to consider as far back as around 1980---anything before that and the numbers are small enough to be within the margin of error.

If we use PADI's data to find a trend, we see that between the 90's and this decade, number of certifications increased around 35%. As there are more certified divers, there will be more advanced certifications and specialties, so let's say growth was 25%. That gives us 1,500,000 new divers for the 90's, and a total of 3,500,000 divers from 1990 to around present.

Doing the same thing for the 80's, we see growth was much larger as total certifications almost tripled. Let's say new certifications doubled, then. This results in about 750,000 new divers during the 80's. I'll round up to 1,000,000 to account for all previous certifications.

Using this very poor estimation strategy, we're looking at around 4,000,000 total certified scuba divers. What does this mean? Not much, really. There are lot of divers out there, most of which haven't been diving in years. I have no sense of how accurate / inaccurate this number might be, although I suspect it is low, due to the long tail provided by many smaller certification agencies. I wouldn't be surprised if the number was closer to 5 million, or even 10 million, for that matter.

Next time we'll look at how many active scuba divers are out there---a more meaningful figure. In the meantime, I'm curious to know in the comments what you think of this number, and if you have suggestions for improving our (poor) guesstimate.

Grouper photo by ansik


Fish Identification: Grouper

In a nutshell: big and ugly---that's what today's fish is. Grouper can be a familiar dive sighting, depending on where you dive. Even the sea bass is technically part of the grouper family, but we'll be treating them separately.
Grouper

Physical description

Grouper have oblong, stout bodies and a large mouth, probably not unlike some of your relatives. Typical lengths are over a meter, and can get to over 2 meters for the various giant varieties.

Their large mouths resemble a frown, contributing to the grouper's unfriendly appearance. If you catch one with its mouth open, you ...


Safety Stop

The first place I ever dove after certification was Bermuda. On one boat dive we were briefed by the divemaster in preparation for our first dive. He asked if there were any questions.

"Yeah, should we make a safety stop", I asked. Fresh out of my checkout dives, I couldn't remember the rules for when to make a safety stop.

The divemaster scoffed at me. "We'll hardly be going deep enough to require a safety stop."

Safety Stop
Fast forward a few years. I've read a mountain of material for fun and as part of my professional development. Looking ...


Wiser in Wellington

A year ago I was working in New Zealand. I was interested in what the local diving had to offer, so I signed up for a small trip off the local coast of Wellington. What happened on that trip turned out to be a valuable learning experience.

It was a cold morning when we pushed off from shore in a small fishing boat, six divers and two crew. I was a little nervous since I knew the water would be cold---it was winter there, after all. I wore an old, uncomfortable rented wetsuit. A farmer john that had seen more ...


Fish Identification: Barracuda

Barracuda actually encompasses a decently sized family of fish (sawtooth, Pacific, great, red, blackfin, and more). However, the differences are marginal, so we'll cover them all together. Over time you should start to look up the species and study the differences. At the least, you should learn the species that live in the region where you dive.

Physical description

[Great Barracuda][]
Barracuda have long, streamlined bodies that are rounded in the middle. Some species (like the great barracuda) can reach up to 1.8 meters (almost 6 feet!) in length, while most are a couple of feet long.

Most species have ...


Scuba Gear Instructional Videos

Scuba gear supplier scuba.com has a cool selection of instructional videos.

Currently, there are 256 videos, with most of them related to product reviews. When shopping for gear, you may be lucky and find one of your potential purchases reviewed. If nothing else, it's a great way to get a feel for a product when buying online.

Digging further you'll find a selection of tutorial style videos. For example, they have a video on maintaining underwater camera o-rings and a video on how to properly clean your scuba gear.

It's a useful resource for those times ...


Fish Identification: Goatfish

Most of the time in this article series we cover a specific species of fish. Today, we are going to broadly cover the entire family of goatfish. There are specific, named species, but in this case it's probably not terribly useful to learn them all.

Physical description

Goatfish
Goatfish tend to be smaller, growing up to about 10 inches (30 cm) in length. There are some species, however, that can reach twice this size. Their bodies tend to be elongated, with a deeply forked caudal fin and two separated dorsal fins.

All goatfish have the ability to change their color ...


More Tips for Improving Air Consumption

Bubble ring
Way back when, we gave a handful of tips for improving your air consumption. Today we have a few more.

  • Be prepared. Have your equipment checked out and ready before you enter the water. Any problems will cost you in air. Also, know your dive site and bring appropriate equipment. If you know you won't need the camera, for instance, leave it behind. It'll improve your air consumption.
  • Beware of free-flowing regulators. Some regulators tend to free-flow often. Be aware if you have one of these so you can catch it as soon as you enter the water ...

Wearing a Snorkel

Snorkeling
Snorkels are considered a core piece of scuba gear. Mask, fins, and snorkel: the three items every beginner starts with. We take this for granted, and dive away with those plastic tubes strapped to our head. After a while, though, we start to question the utility of a snorkel. When diving the smooth Caribbean waters, for example, is a snorkel really necessary?

At this juncture, there are a few paths the blossoming diver can take:

  • Keep the snorkel. Your first option is to heed your training and continue to dive while wearing a snorkel at all times. Sure, it can ...

Fish Identification: Dolphins (Part I)

I thought we'd do something a little different today. Everyone is familiar with dolphins in some shape or form, but did you know there are 18 genera (plural of genus) of oceanic dolphins? We are going to cover some of the more common ones. Then you can look smart when someone shouts "Dolphin!" and say, "More specifically, that's a Pacific white-sided dolphin."

Common Dolphin

Common dolphin

It's called the common dolphin, but is probably not the most familiar. There are over 20 species of common dolphin, in all shapes, sizes, and colors. Generally speaking, the common dolphin has a ...