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SDI Solo Diver Course with Big Blue Diving, Koh Tao.

Sunset over the ocean in Koh Tao, Thailand in front of Big Blue Diving

I am not sure when the idea of doing a solo diver course popped into my head. It might have been last year in the Maldives when I found myself panicking in an underwater washing machine with no clue what to do but cling to my amazing divemaster.


I lived to tell the tale but it made me realize that despite being a divemaster myself with over 200 dives under my belt I often feel highly unprepared. On the surface, literally and figuratively, I know what to do but deep down I often think I should be a better diver and know more about what to do in an emergency or a new situation like said washing machine.

But after having finished my divemaster training, I wasn’t sure for a long time how to go about it – what course was there? How to become a better, a more self-reliant diver? That was the question.
With those words ringing in my mind I came across the PADI self-reliant diver course and started to do some research – maybe solo diving was the way to go. Not to actually dive by myself but to learn how to handle myself better underwater.

I started to look into options and asked around in my beloved Girls that Scuba group to get feedback and find a reputable dive center. I was on a budget so a place like Mexico where I had met some amazing instructors was out. To be honest, I wanted my cake and eat it too – I wanted a great teacher and pay as little as possible. I know how that sounds…


Sunset over the ocean in Koh Tao, Thailand

With the matter of costs firmly on my mind, I started to look at Koh Tao again. Koh Tao has a special place in my mermaid’s heart. I learned how to dive here and also did my DMT on the island, two vastly different experiences.

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If I had learned one lesson from my DMT it was to do better research on where I would spend my money. So I asked around for dive center recommendations on Koh Tao for my solo diver course. The one name that came up frequently was Big Blue Diving Koh Tao and so I finally wrote an email.
Within a couple of hours, I had an answer from Andrew who heads up Big Blue Tech, the technical diving department of Big Blue. He told me that they don’t offer the PADI self-reliant diver course but SDI Solo Diver. SDI (Scuba Diving International) is the recreational side of TDI (Technical Diving International), one of the most regarded tech diving agencies in the world.

If I had learned one thing is that agency doesn’t matter as much as your instructor though to be honest I wasn’t sad to forgo PADI. I told Andrew as much but also discussed with him that I wanted to meet any potential instructor before committing to the course. He agreed and I booked my tickets to Koh Tao.

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Back on the island, I made my way to Big Blue which has its dive center, restaurant, and adjacent hostel located at the end of Sairee Beach. I met with Andrew and his lovely wife Fiona, one of the instructors. We had a long chat about diving in general, my previous dissatisfying experience on the island, the SDI Solo Diver course, and life as we know it. I was pretty much immediately sold by Fiona and her friendly no-nonsense approach to diving and booked my course for the next couple of days with her.

What is solo scuba diving?

As the name implies an SDI solo diver course (or any other solo diving course) teaches you the art to dive on your own. This is unfathomable for many divers as one of the most important rules of diving all new divers learn is: never dive alone.


As a recreational diver, you learn to never go anywhere without your buddy underwater. However, there are times when you might want to dive on your own. As a photographer, for example, your chances to get close to cool fish and critters are much better alone and on your own, you won’t keep your group waiting either.
For me, the more important reason was that you cannot always rely on your buddy for help if something goes wrong. Even a certified diver might panic and if someone is fairly new chances are they will not know what to do in an emergency. I wanted to learn more self-reliant and be able to help myself as well as others if need be.

With those goals in mind, you learn how to plan dives on your own, practice how to set up and deploy an alternate airsource and get familiar with the concept of deconditioning panic by repeating certain movements over and over again so you will instinctively know what to do in an emergency. This includes handling a free-flowing regulator, switching masks underwater, and deploying an SMB.

You also practice your navigational skills with a compass and last but not least you have to put it all into practice. But more on that one later…

As with many scuba diving courses, the SDI Solo Diver also has a theoretical and a practical part. For the theoretical part, you will do some e-learning as well as a ‘classroom’ session, and do an exam afterward. The practical part is divided into an underwater skills lab which is either done in the pool or confined water and usually 2 open water dives (though I ended up doing 3 – hurrah!). And if you pass all your requirements you should be done within 2 days.

My SDI Solo Diver Course

White board with SDI solo diver course lesson

Fiona and I started our morning over coffees and hit the books. While you can do most of your studying with the e-books I always prefer discussing some things directly with an instructor (so I can be the annoying one with all the questions…).

For my SDI Solo Diver course, I had to learn how to plan dives. That is something I hadn’t done in a long time and for a solo diver, a dive is planned somewhat differently and a lot more conservatively than you would when heading out with a buddy. For the calculations, we had to determine my surface air consumption rate which meant breathing from a tank on land for 20 minutes. With the rate in tow, Fiona showed me how to plan a dive before we set out to the boat for our skills session.

Fiona too is a technical instructor which meant for me that I was getting my first introduction to tech diving at the same time. At 10 m depth she set up a line between some concrete blocks and not only was I to do my skills I was supposed to do them in perfect tech diving trim – completely vertical and not wavering too much above or below the line. Let’s just say I have never sweated as much underwater and Fiona only told me afterward that this was not part of the course requirement…puh.

During my skills she showed me how to switch to a sling or a pony bottle which is basically a small tank you take as a backup on a solo dive lest your main tank, the hoses, valves or regulators malfunction. Strapped with that extra tank in front of me, a second mask on my side, 2 computers and a compass on my wrists I felt more like a pony myself.

But my little pony and I managed quite well and I got all my skills done including the dreaded mask swap, never an easy task even if you are not wearing contact lenses as I do. Fiona and I even had some time to practice BCD removal underwater, a special request I put in after I had to deal with a loose tank strap on two of my Maldives dives.

After a surface interval of pandan cream cookies (the kind that only tastes good after diving!) we headed to Twins, a well-known dive site in front of Nang Yuang island for a navigation dive. Let’s just say that my underwater navigational skills aren’t the best and that was happy to be able to blame getting a little bit lost on the bad visibility.

Beach and leaning palm tree on Koh Tao Thailand

Once we were back on dry land, Fiona briefed me for the next day and my solo dive. It only dawned on me then that doing an SDI Solo Diver course also meant to actually do a solo dive (as my friend Claire smartly remarked when I told her about my jitters ‘wasn’t the name of a course kind of a giveaway?!’).

The next morning we set out early to Chumphon Pinnacle, a favorite dive site for many Koh Tao divers. I was less nervous now because chances to get lost diving around a pinnacle are somewhat slim – even fro me. Still, it was an adventure and after we planned my dive in minuscule detail Fiona told me I could not stay a minute longer than the planned 35 minutes dive time. In addition, I had to request permission from the head divemaster of the boat and clock in an exact return time – I would have to be back on the boat no later than 8.45 am. If I didn’t make both of these times I would fail my course requirement. Ups.

Just like a mother taking her child to school on the first day, Fiona took me down the buoy line to 25 m where my dive was supposed to start. She explained to me before that I was to simply go off unless she would tell me otherwise underwater due to unforeseen conditions. Clear visibility and no current and I headed off without turning around. I did feel like a kid on her first day of school and so I hugged the sling bottle in front of me tightly, mustered all my courage, and went off on my own. Luckily there was a huge school of trevallies waiting for me which made it all better. I immediately felt back at home underwater and the lack of a buddy didn’t change that.
As it goes with solo travel I also relished being on my own underwater. No compromise, no noise. Mind you, Chumphon Pinnacle is a busy dive site and there were plenty of other divers around. But nobody paid attention to me which made me a bit sad because damn I felt proud diving on my own!

Gili Air Divers

I observed giant groupers, lots of Nemos and even practiced my new tech diving trim until my hips hurt. In the meanwhile, I kept a watchful eye on my compass and the three buoy lines. I surrounded the pinnacle a lot faster than I realized but luckily it really is quite hard to get lost at Chumphon and so I found myself at the right line when it was time to come up. Now I realized that I needed to get going if I wanted to make my safety stop and return to the boat in time. My beeping computer reminded me to slow down and so I got my bearings, deployed my SMB, and used my safety stop to head towards the two ladders of our boat.

My head popped up and my computer showed 34 minutes dive time. Fiona was waiting for me and beckoned me to get up quickly, our boat was about to move up a slot on the buoy line. I had just made it and once again I felt incredibly proud.

We did a quick de-briefing before heading to a leisurely dive at White Rock. Since I had mastered all my course requirements, I left the bothersome sling bottle on the boat, and we enjoyed a fun dive instead. And just because I am a brownnoser I asked Fiona for an impromptu lesson in backward finning, a skill I realized needs more patience than I can muster at this point.

Back on dry land, I had to finish my theoretical exam before Fiona handed me my SDI Solo Diver certification. Over a few beers, we resumed about the experience and my diving future. I realized that for the first time in a long time I felt proud of my accomplishments, happy to have found a new diving mentor, and excited to learn more – solo or other.

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  1. CONGRATS!!! it is definitely something to be proud of.

    1. thank you so much 🙂