I admit it. The articles I write for The Diving Blog tend to be PADI-centric. Do I think PADI is better than all the others? Not really. I did my Open Water certification with PADI and just happened to move through their system. I’m working on a PADI divemaster certification (and soon, Open Water Instructor).

To introduce a little fairness, I decided to investigate several agencies and report on the differences. The result may not be a big surprise. The differences between agencies are small. When you dig deeper you uncover the reason for this. There are international (and national) standards for certification requirements. That is, representatives from different agencies agreed upon the minimum knowledge and skills required for each certification level.

This has two implications. First, it means scuba training across the board is going to be very similar. Fluctuations in instructors are more likely to determine your individual experience. Second, it means most agencies follow the same certification hierarchy: open water diver, advanced open water diver, rescue diver, divemaster, assistant instructor / instructor. Names may very slightly, but the overall structure is the same, with each of these courses following the standards set forth by ISO 24801-2 (open water), 24801-3 (divemaster), 24802-1 (assistant instructor), and 24802-2 (instructor). The important thing here is that most standard-respecting agencies will respect comparable non-professional certifications from other standard-respecting agencies. Sometimes a peek at your log book may be required, or worst case, an accompanied dive to demonstrate your skills. Call your destination’s dive shop ahead of time if unsure.

There are a lot of certifying agencies. For my research, I looked into those that are a) international, and b) the largest. Here some information about each of those:

Professional Association of Diving Instructors (PADI)

PADI is by far, the largest certifying agency in the world, with over 5700 dive shops and resorts in over countries. It was founded in 1966, by effectively splitting off from NAUI out of frustration.

PADI revolutionized scuba instructor by turning it into an hobby for everyone, rather than elite swimmers and athletes. The learning material reflects this, by breaking down every process into distinct pieces for easy consumption. This approach to learning extends all the way up the ladder to divemaster and instructor levels. Instructors are expected to adhere to every aspect of the PADI system, not only what is taught, but how it is taught. This makes the PADI system incredibly consistent across the globe.

Being the largest certifying agency (issuing two-thirds of all certification cards in the US each year) comes with its criticisms. First, is how PADI constantly attempts to upsell its customers. The entire last chapter of the Open Water manual is an advertisement for Advanced Open Water. Almost the entire divemaster manual says why you should immediately go on to the PADI instructor-level. PADI is a for-profit corporation, and this sometimes reflects in their material, with many jokingly referring to PADI as, Put Another Dollar In.

The second criticism, however, has less of a basis. Many claim that PADI “dumbs down” scuba diving for mass consumption. It is true that they break the learning process down into its simplest components, but this can hardly be considered a bad thing. This elitist attitude neglects the advantages that have come from the boom in scuba diving, namely easy access to dive sites and equipment practically anywhere in the world.

National Association of Underwater Instructors (NAUI)

NAUI is the oldest certifying agency in the world, established in 1959. NAUI even boasted Jacques Cousteau as a member of its advisory board at one point. Another distinction belonging to NAUI is that it is also one of the few non-profit agencies (the only big one, as far as I can tell). NAUI’s reputation has earned it a spot as the certifying agency for many colleges and universities, the US Navy, and even NASA.

While not a member of Recreational Scuba Training Council (RSTC), NAUI is ISO certified.

Scuba Schools International (SSI)

SSI was founded in 1970, and has over 2400 offices in 110 countries. SSI takes a unique approach, in that training is only provided through one of their worldwide centers. Despite this centralized approach, SSI gives its instructors more freedom in how material is presented, giving instructors the opportunity to adjust style based on student participation. I suspect their centrist policy allows this freedom, since instructors are teaching within a dive center where styles and student reactions are easier to monitor.

SSI emphasizes its teaching style of “comfort through repetition.” I don’t see how this is much different than most agencies, but the most noticeable result is that SSI requires five open water dives for basis certification, rather than the four required by the standard (and followed by most agencies).

Scuba Diving International (SDI)

SDI is the recreational arm of Technical Diving International, the largest tech diving training organization. It is also the baby of the group, recently founded in 1999. Despite getting a late start, SDI now has over 2200 authorized dealers worldwide, putting it just a hair behind SSI in size (although I don’t know the geographic distribution of either).

While a standards-recognizing agency, SDI is unique in two ways. The first is immediately noticeable in their Open Water course: all students are required to have modern dive computers. SDI gets students used to diving with computers from the start. This could be seen as an advantage, since it eliminates the need to teach dive tables and introduce further confusion. I have also heard this as a criticism, since should a computer fail, the user is left with no alternative means of dive planning.

Secondly, SDI is the only agency that offers a certification for diving alone, Solo Diver. Every other agency mandates diving with a buddy at all times. I imagine this aspect of SDI was influenced by its origins as an offshoot of TDI, where diving alone is normal.

If one of these stands out to you, or you find their teaching philosophy appealing, then go with it. Otherwise, don’t fret about any particular agency. Instead, spend your time finding high-quality instructors, either through recommendations or online reviews.

Is there any other reason you would suggest one agency over another? What is your experience diving abroad with the smaller organizations?

Following basic certification, many divers immediately move on to an advanced certification level. Especially since some activities (like deep dives) require an advanced card.

Advanced certification has been criticized for being somewhat of a misnomer. In all certification agencies, the advanced level is attained with a relatively small number of dives. For this reason, it has been suggested to rename the advanced open water level to something like, “Open Water II” (as it was previously called by NAUI) or “Comprehensive Open Water”, to better indicate the nature of the course. Regardless of what it is called, those that dive regularly will want to complete the course at some point.

Advanced certification is built around specialities. The idea is that exposure to many different varieties of diving increases your experience level and encourages further development. How much exposure is required differs between agencies. I’ll cover the four largest.

PADI

PADI requires five “adventure” (i.e., specialty) dives to qualify for Advanced Open Water (AOW) certification. One of these dives must be an Underwater Navigation specialty and another the Deep Diving specialty. The other three are the diver’s choice. (Note: Until 2006, night diving was required.)

Unlike other organizations, PADI does not require a minimum number of dives for certification. This means that a diver could be Advanced certified with only 9 dives (4 open water dives + 5 adventure dives), all of which are instructor certified. This makes PADI’s AOW certification the quickest, and the easiest to criticize.

NAUI

NAUI calls their second certification level, “Advanced Scuba Diver”, with requirements similar to PADI’s. However, NAUI requires six open water dives to qualify for certification. One must be navigation, another must be deep diving, and a third is required to be night or low visibility diving. The other three are chosen at the diver’s discretion.

Also like PADI, there is no minimum number of dives required. With only one additional dive required, NAUI Advanced certification is almost as quick as PADI.

SDI

SDI prides itself on its Advanced Diver Development Program having higher requirements and demanding more experience before certification. As opposed to just a certain number of speciality dives, SDI requires candidates to complete four specialty courses, with no requirements on the type of specialties. Each specialty requires about two dives, so eight dives total.

Another distinction is that SDI requires a minimum of 25 logged dives to complete certification. Once reached, the scuba diver brings in their dive log and four specialty cards to be awarded Advanced Scuba Diver certification.

SSI

SSI’s Advanced Open Water Diver certification is more similar to SDI than any other agency. They also require completion of four specialties, with no requirements on the specialty subjects.

24 logged dives are required to complete certification.

This should give you an idea of what’s required to complete Advanced certification. The student must decide what specialties they want to explore. In my opinion, the most valuable non-required dive is a buoyancy related specialty. Proper weighting and buoyancy control throughout a dive are valuable skills to master early. Other than that, it should be straight-forward to follow your interests in deciding.

What specialities would you recommend? What do you think about the whole “Advanced Diver” misnomer?

One fish I really enjoy spotting is the spotted drum. It’s not uncommon to find one, but it’s infrequently enough where they’re not boring.

Physical description

Spotted drum are about 6-9 inches in length (about 20-something centimeters). If you see one, you will know it. It is an easily recognized fish that is white with broad black stripes in varying directions. The dorsal fin and tail are usually adorned with white spots. If that isn’t distinguishable enough, they have a long, white and black “feather” connected on top of their body, between the head and dorsal fin.

Geography and Habitat

Spotted drum are found on coral reefs in the Caribbean, Gulf of Mexico, Florida and the Bahamas. They can be found at all recreational depths. They swim alone, usually under cover of a ledge, coral, or the opening of small caves. For this reason, you will need to get low to find them.

Spotted drum are nocturnal, so it’s possible to find them out feeding during a night dive.

Further reading

Fishbase.org

I recently came across this article on world travelers who make their money online. The first profile is of a British couple who travel the world as dive instructors.

Ben Stokes and Sarah Kemsley met on vacation in Malaysia (while diving, I assume). Neither of them returned to school, and instead live abroad setting up dive tours. They spend 3-4 months at a time in various locations. Indonesia, Thailand, Egypt, Honduras, Belize, Fiji—their home bases read like a top dive destination list from a travel magazine.

I imagine it is difficult keeping a steady stream of customers working in this fashion, especially in the highly-competitive dive market. The trick, as the article suggests, is keeping their living expenses to a bare minimum. It’s not for everyone, but I think their chosen lifestyle is very cool. For the interested, it looks like they keep a mildly-updated blog of what they’re up to.

Hats off to Ben and Sarah for living their dream!

Need a gift for that special diver in your life? You may think diving-related gifts always break the bank, but here’s a list of mostly inexpensive ideas. Some of these can be extremely handy gadgets for a diver, even if she would never think to buy it for herself.

• Retractors, clips, etc. – These little guys can be immensely useful.
• Fancy dive log – Is your partner crazy about maintaining a meticulous log book? Maybe one of these is for him.
• Spring fin straps – These things are great for slipping open-heeled fins on and off easily.
• Mask cover – We’ve talked about how awesome these things are.
• Noisemakers – Get a pair of these, one for each of you. Check out your options at our article on noisemakers for scuba divers.
• Dive knife – Depending on where they dive, a knife could be useful. Nothing says I love you like weaponry.
• Dive bag – A very practical gift, since we all have to haul our luggage around somehow.
• Spare parts kit – Especially good for the tinkerer.
• Dive light – Not the cheapest gift, but good if your significant other enjoys night diving, and always has to rent a light.

What are your clever gift ideas for scuba divers?

Split fins are a relatively recent invention, developed in the late 90’s. They are easily recognizable as fins that are, well, split down the middle. Before we get into them, let’s talk about basic fin design.

The purpose of fins is to convert the up-and-down motion of a kick into forward thrust through the water. The more efficiently it does this, the less energy it requires for you to move, since a higher percentage of kicking energy is converted into thrust. This efficiency is generally what makes one fin considered “better” than another.

Most full fin designs have some sort of ribs on the edges and possibly in the middle, creating channels along the fin. This directs water along the fin, ensuring that most of it gets pushed backwards, in turn pushing you forward. The ribs prevent water from “spilling over” the edges of the fin.

This is straight-forward, but things start getting fancy with split fins. Split fins are in principle similar to a propeller, which uses hydrodynamic concepts to turn rotational motion into forward motion (i.e., the blades spin and the plane / boat moves). As you kick, the fins angle inward, forcing water down a narrow channel. This creates a pressure differential that, along with the water running down the channel, helps propel you forward. (Note to physics geeks: see Bernoulli’s Principle)

Ok, sure, but what does it mean? Basically, that you get more motion for the same amount of kick. Split fins are more efficient and thus, “better” by some definition.

It’s not all good, though. This description only applies for the usual flutter-style kick. If you are a frog kicker, split fins will actually be less efficient than ordinary full fins. For this reason you won’t see split fins on a lot of wreck or cave divers.

Split fins are also expensive, costing 2-3 more than regular fins. It’s up to you, whether the extra cost is worth the increased kicking efficiency. Besides, fins are probably not the most expensive piece of scuba equipment you’ll buy (even split fins), so when you factor in their lifespan, the extra cost becomes less significant.

I use these split fins from Apollo. Although I haven’t had much experience with other fins, I really enjoy them.

In the end it comes down to the importance you place on kicking ease and your budget. However, next time you shop for fins, at least check them out and see if they work for you.

In previous tips for underwater photography, we covered the importance of using flash to supply the color absorbed at depth. Sometimes you can’t use it, though. For example, in scenery type photos where there is nothing to get close to and use a flash. These pictures are going to be very blue, and its up to your camera mode to adjust the color balance, or you have to do it manually afterwards.

Manually color-balancing photos is a lengthy topic, and one we’ll get to someday. But today, I have a super-quick way for you to restore color that may work for a large number of pictures. Unfortunately, I only know how to do it in Adobe Photoshop, but other programs probably have comparable features.

Here’s the example photo we’ll be adjusting. The strong blues are easy to notice.

Open the photo in Photoshop (make a copy first). Then select Image -> Adjustments -> Auto Color.

Voila! Using some simple algorithmic trickery, Photoshop can see that the image is predominantly blue and correct for this.

Could the photo use some manual adjustments? Probably, but for the quick jobs not appearing in Scuba Diving Magazine, this will often do the trick.

If you know how to get the same effect in other programs, please post in the comments and I’ll update the article.

A fish commonly encountered during Caribbean reef diving is the bar jack. Other English names include blue-striped cavalla, red jack, neverbite, passing jack, skipjack, and pointnose, although I believe bar jack to be far more common.

Physical description

Bar jacks have a horizontally symmetric shape, and bear a remarkable resemblance to the fish symbol . They have a forked caudal (tail) fin, which implies they are quick, continuously-moving fish. They have dorsal, anal, and pectoral fins, although these are generally hard to see until the fish is close. They are moderately-sized fish, usually a little over a foot long (40 cm).

The bar jack’s most distinguishing characteristic is the black stripe running along the top of the fish, down to the bottom of the caudal fin. Often there will be a vibrant blue stripe immediately below the black, making the bar jack immediately recognizable. The rest of the fish is a silvery color. Juveniles are not as easily distinguished, and can have up to 6 dark bands.

Geography and Habitat

Bar jacks are found in the western Atlantic, along the east coast of the US down into the Caribbean and Gulf of Mexico. They extend from the coasts of New Jersey down to Venezuela, and have even been found as far south as Brazil. They are uncommon in the northern Gulf of Mexico.

The bar jack likes clear, shallow waters, making it a familiar sight near coral reefs and to depths of around 60ft / 20 m. Studies have found that the species moves quite a bit from reef patch to reef patch, even over large regions of sand. As a diver, this means you will often see bar jacks hovering above or away from the reef, rather than in the coral as preferred by many fish.

Bar jacks can be found swimming alone, with a few other fish, or in a school of many fish. That’s not very helpful for identification, but fortunately the bar jack is easy enough to spot without relying on it’s social behavior.

Further reading

Wikipedia
Florida Museum of Natural History