BEA Wander

Scuba Diving: Getting My Open Water 20 Certification on Koh Tao

17 min read

My first time underwater was in a lagoon in Hawaii. Then, I swam with manta rays at night. 

It was magical! 

These gentle giants have no teeth and feed on plankton.

2 females. One chest-bumped me.

I was told we can’t touch them, but they can touch us (like a stripper).

This was back in March 2017. 

Getting my scuba diving license was on my bucket list since then. 

Was it hard to get the Open Water 20? It wasn’t easy…

Was it worth it? Hell to the YES!

Here’s how it went!

7 Dive Schools I Looked Into

Dive Sites all around Koh TaoKoh Tao is one of the best places in the world to scuba dive.

There are about 30 dive sites and 120+ dive schools around this little island.

Pricing standards are enforced upon by “The Koh Tao Dive Club” – a regulatory authority governing safe and fair scuba practice on the island.

This means that all schools offering Open Water 20 costs (a minimum of) 11,000 baht. 

Besides the same price, you’ll get 4 dives to test your underwater skills, some sort of discount on accommodation and our license never expires. 

You might need to do a refresher course if you haven’t dived in 6 months or 1 year, but your scuba diving certification is good for life! 

So, how did I pick my school?

Well, I paid attention to a few things while talking to each one:

  • Customer Service
    • How detailed were their answers to my questions? Did they actually answer ALL my questions? I had a lot…
  • Facebook Page Ratings
    • I looked at the number of likes and read the reviews too – quantity and quality
  • Did any of my friends go with them?
  • Other things:
    • How many days is the course? Is there extra payment on top of the 11K? What’s the course work like? What’s the max # of students in a group?  

I talked to 7 schools, shortlisted my top 2 and chose the one I felt most comfortable with.

1) Ban’s Diving Resort

I’m sure this school is just fine. I just didn’t get a lasting impression from them. Website here

2) Big Blue Diving Koh Tao Beautiful beaches on Koh Tao

One of my friends went with Big Blue and had an amazing time. Website here

3) Coral Grand Divers

I’m sure this school is fine too. Website here

4) Crystal Dive Koh Tao

I think they spend the most on Facebook Ads lol 

Another friend of mine went with Crystal. 

Maybe because they’re a PADI only dive school, I felt like I was getting pushed to do the PADI and that there are no other options. Website here

5) Hydronauts Diving

When I was crowdsourcing for the best dive school on FB groups, this one came HIGHLY recommended by a few divers.

I tend to like things that aren’t overly popular, so a smaller, more intimate school sounded great! Website here

6) Phoenix DiversChilling at the beach on Koh Tao

Again, I’m sure this school is just fine too! Website here

7) Roctopus Dive

There were also a handful of people who RAVED about Roctopus on the FB groups.

I also loved how the person I communicated with was quick and super thorough with her responses.

She answered ALL my questions and then some! Website here

8) (BONUS) Sail Rock Divers

Just to make sure, I even talked to one dive school on Koh Phangan. 

Cost is 12500 baht, but they said it’s only usually 1-2 students in a class. Website here

Here’s my decision-making process:

Koh Tao Scuba Diving Schools - Compare & Contrast
My top choice was Roctopus with Hydronaut as a close second.

Since both scored relatively the same, my final deciding factor was gut feeling. 

I know, pretty subjective.

But if I’m going to put my life in someone’s hands, I need to feel 100% good about it!

Obviously, I knew I wasn’t communicating with my actual dive instructor, but still – they’re a representative.

PADI vs SSI vs RAID - What's the Difference?

Just a quick note on this.

The main 5 agencies are RAID, SSI, PADI, BSAC & TDI.

All are internationally recognized and part of the Recreational Scuba Training Council (RSTC). 

A lot of people will mainly know of PADI (and maybe SSI). 

This is due to their awesome marketing efforts, and it helps that they’re the biggest agency.

The majority may think that PADI is the only way to go, but they’re only just one agency and no more recognized than any other agency in the RSTC.

Think of them like brands. 

Nike. Adidas. Puma.

No matter which one you choose, the end goal is to get a good pair that fits your feet.

Open Water 20: How Did It Go?

Uh…Considering that I got my certification – really well! 

Water Open 20 Scuba Diving License - with Roctopus in Koh Tao

Before I take you through it day-by-day, let’s go over the prerequisites first. 

You need to be: 

  1. Minimum of 12 years of age
  2. Able to float 10 minutes unassisted (usually in the pool)
  3. Able to swim 200 meters with no swim aids or 300 meters using mask fins & snorkel (usually in the pool)
  4. Medically fit to dive – you’ll need to fill out a medical questionnaire

No problem? Perfect!

Problem? Talk to your dive school!

Day 1 – Orientation

Orientation at Roctopus Dive in Koh TaoEnergy Depletion Level: 20%

We all met at the school at 4pm for 2 hours.

There were a total of 6 students for the Open Water 20, so we split up into 2 groups of 3 with 2 instructors. 

In the first hour, we walked through the schedule for the next 3 days and went over some housecleaning items. 

For example:

There’s an option to pay 2000 baht (split between the 6 of us) for a videographer to film us diving.

If we wanted to do the Advanced Open Water, we get a little discount.

Free EcoTrust Tote Bag from RoctopusWe also got some free swag: 

  • Tote bag
  • Branded waterproof bracelet
  • 10% discount card at popular restaurants – only valid for the duration of the course

In the last hour, we set up our profile on the Dive Raid website/app. 

And some homework was assigned. 

Online Course Work

That night we needed to read 4 modules and pass each quiz at the end. The next night, the same thing with 3 other modules. 

Some of it is interesting, some boring and some technical.

RAID online course work - module 1- Diving in GeneralDon’t worry – everything will be covered in the classroom again in more detail.

I booked and paid for my OW20 a month prior, so I got a headstart on the reading and finished all the quizzes before I arrived on Koh Tao. 

This way I was able to do the readings at my leisure and had my evenings free during the actual course! 

I still reviewed the quizzes at the end of each module though.


Because there’s an exam on the 3rd day. 

Trivia facts I learned that day: 

  • We only retain something like 20% of the water we drink
  • 12-year-old kids can do Open Water, so I should be fine.

Day 2 – Classroom & Pool Time

Energy Depletion Level: 70%

8am start!

We met our instructor – her name is Beth. 

Fitting Scuba MasksShe’s the BOMB!

This funny Brit is a natural teacher – very patient and animated. 

I told her that sometimes when I’m zoning out (come on, most people’s attention span is equivalent to a goldfish’s nowadays), I still get what she’s saying by just watching her act it out. 

Her enthusiasm is infectious, even at 6am. Definitely, someone you want to be watching your back in the open water! 

We had theory until around 10:30am, took a 1H break, then got changed and set up our equipment to get in the pool. 


We were in the pool for 5 hours. With breaks, of course. We all had to put on another layer of a wet suit.

We did our tests: Learning about our scuba equipment with Roctopus Dive

  1. Swim (any style) for 200 meters

    Man, I don’t usually swim – just not my choice of exercise – and it really showed. It was so much cardio for me!


  2. Float for 10 minutes

The float test was difficult at first but I learned to surrender. Near the end, it was quite calming. If you ever floated in a tank before, it was like that.

Pool time is for getting used to your equipment and wet suit, learning how to stay in neutral buoyancy, remembering hand signals, and just getting used to breathing and moving underwater.  

We did a LOT of emergency situation skill tests. 

For example: 

  • What happens if you run out of air? 
  • What happens if your main regulator comes out of your mouth? 
  • What happens if your buddy runs out of air? 
  • How do you take off and put on your scuba gear in the water? 
  • How do you clear water out of your mask?

This is good because we will be doing the exact same thing in the ocean over the next 2 days! 

Better to practice and get all the mistakes out of the way now, especially in a controlled environment. 

I tan too easilyClass was dismissed around 5pm. We ate dinner at 6pm and passed out around 10pm. 

Trivia facts I learned that day: 

  • At resting state, the average person takes about 10-20 breaths in a minute
  • Sound travels 4x faster underwater, so it sounds louder
  • We lose body heat 200x faster underwater
  • Pool water can be much colder than the ocean
  • I tan REALLY easily – it was a cloudy day and I still got this weird wet suit tan!

Day 3 - Classroom, Exam & Dive 1+2 (12 metre)

Energy Depletion Level: 100%

We had our last theory session at the restaurant next to the school, then did the exam. 

There are 45 multiple-choice questions. You need 80% to pass – that’s 36/45.

A few things:

  • You can take as long as you want.
  • You can re-take the exam as many times as you need.
  • It’s open-book

Taxi to Koh Tao PierIt took us about 20 minutes to complete and we all got the same score: 44/45. 

Congratulatory high-fives all around! 

If you paid attention in class and did your readings, you should pass.

1H break later, it was time to taxi to the pier together. A taxi down here is in the back of a pick-up truck.

Dive 1 – Twins Dive Site

The boat was so rocky I had to take a seasick pill. 

Getting Ready for Dive 1 of Open Water 20Made from ginger, it was non-drowsy. I also knew the motion sickness would go away when I’m underwater.

Twins is beside Koh Nang Yuan – the private 100 baht island.

The surface waves weren’t ginormous but still big, and the visibility wasn’t great – about 5-8 meters. 

We repeated some of the skill tests we did earlier in the pool.

Such as: clear water from your mask, save your buddy who is out of air, stay neutral during 3 minute stop at 5 metre mark and take your equipment off and put it back on. 

It definitely took some getting used to being in the ocean. There are a lot of distractions:

  • Your buddy not being able to equalize, so you got to stay with them
  • Waves just throwing you around
  • Fish and other divers everywhere
  • Everything was so salty
  • Dry throat from breathing from your mouth only

The biggest thing was learning to control my buoyancy and not float up. 

I struggled with that big time – needed another weight to keep me down. 

Before we know it, time to get back on the boat.

Dive 2 – Pottery Dive Site

Surfacing from Scuba DivingWe sailed 10 minutes to the next site.

The surface waves grew even bigger! 

I was not prepared for this and tired myself out quickly.

I was stressed out as I struggled against the waves trying to swim to my team so we can descend together.

A mini panic attack set in – I wasn’t sure if I could go down again.

My heart was pounding, my breathing ragged, my muscles fatigued. 

For a split second, I thought to call it quits and tell Beth I needed to get back on the boat. 

But NO!!!

This is when being stubborn comes in handy!

I couldn’t let my fear win. I can’t let myself down. 

The truth was:

If I admit defeat, I wasn’t sure if I could gather the courage to dive again. 

A million thoughts zipped through my mind: 

Calm the FUCK down. You’re fine. Just breathe – slow inhale, long exhale. 

It’s better underwater. Your team is here with you – you’re not alone. Mind over matter. The dive will only last 40 minutes. Be greater than your environment.

Girl. a 12-year-old can do this! 

And, guess what? 

It was better when I got down to the bottom – enjoyable, in fact. 

Trying on Scuba Diving Masks at RoctopusOh, I did something stupid. 

As we were preparing to get into our equipment, I had the chance to defog my mask.

I thought – Nah, it’s already on my face, it’s fine and I’m tired/too lazy. 


My mask kept fogging up the whole time – it was so annoying. 

This dive I got better at buoyancy control – I finally learned to use my lungs. 

We completed more skill tests and went back up!

As I was going up the ladder on the boat, the waves were so strong that it dragged my leg across the step wrapped with rope, and I ended up with a rope burn. 

Surprisingly, it didn’t bruise! 

Overlooking the air tanks at other boatsLooking like a drowned cat, I was back on the boat drinking hot water and eating biscuits with pineapples.

As we sailed back to the pier, we dismantled our equipment and put them back in their proper place. 

When we arrived back at the Roctopus headquarters, we washed and hung our gear to dry for tomorrow, then logged our dives. 

Class dismissed. 

I bee-lined back to my place, so I can take a hot shower first.

We ate at 6pm, slept at 8pm and woke up at 5am the next morning. 

The whole time we still felt like we’re floating in the water.

Things I learned:

  • When the surface waves are that big, you’ll never feel like you’re in control – just surrender. It may feel like you’re drowning, but you aren’t. You’re inflated, you’re safe. Just swim back to the boat or to your team.
  • Scuba diving is 60% a mental game and 40% physical – be prepared for that.
  • I can’t pee in the ocean – I really wanted to (lol) because it’s a hassle to remove your wet suit and swimsuit to pee in the dirty toilet on the boat. Everything will just wash out into the ocean anyway – so there’s no real difference. But I couldn’t – I don’t know what the mental block is. 

Day 4 - Dive 3+4 (18 metre)

Energy Depletion Level: 90%

Met at Roctopus at 6am, had a short briefing, and taxied to the pier. 

I prepared myself mentally on the drive there. I told myself to “make the ocean my bitch” – I think it helped 🙂

I felt ready to tackle the morning – I had a ‘let’s do this’ attitude.

By 8am, we were in the water.

Dive 3 – Twins & Dive 4 – White Rock

On way to dive point for Open Water 20Remembering my mistake from yesterday, I washed my mask with soap before both dives.

I went in the water with a different approach for each dive: forwards (Stride) and backwards.

Both times, saltwater just got all up in my nose, which didn’t happen yesterday though…weird.

I enjoyed myself a LOT more this time around!

I was more confident, comfortable and knew what to expect.

Had better buoyancy control. 

Was able to pay attention to my surroundings and actually appreciate the different fishies and coral.

The skill tests were a breeze.

Passed all 4 dives of OW20One thing though.

Our group was swimming a bit too close together and we often kicked or crashed into each other.

Minor inconvenience! 

Oh, we had a Dive Master trainee tag along with our group. All 3 of us felt more at ease with essentially a second babysitter. Haha!

I lost my Dive leader and Buddy for two seconds.

Dive Master trainer to the rescue! He tugged on my leg to get my attention and pointed to where they swam. 

I felt really good about the whole day – before I got in the water, during and after I got out.

As I got out of the water, high off 2 really good dives, a song was stuck in my head. 

Not a song I listen to often, so I don’t actually know the words, but the part that kept replaying was:

“She’s got style, she’s got grace, she’s a winner”  

What Did I Learn?

Let’s put the ‘how to survive underwater’ thing aside. 

I saw a lot of parallels to life in general: 

  1. Control and security are illusions
    • Learn to surrender to the chaos. You’ll find that things get easier when you just accept this truth. Going back to Pra KK at the meditation retreat in Chiang Mai – let it happen, let it go and don’t dwell.


  2. When life knocks you down, get back up and try again
    • I realized this on Dive 2, as I was fighting against the BIG surface waves. One girl in our group decided to not continue in the course after the first dive. No refund, unless it’s a medical condition. Sorry!


  3. Life (and scuba diving!) is a mental game
    • You’re only in competition with yourself, no one else. Almost everyone is physically capable, but the ones that don’t make it through the dive course is because they couldn’t overcome themselves mentally. 110% agree!

Whatever you’re facing right now, someone less capable than you has done it and succeeded. Get out of your head and don’t stand in your own way. 

Would I Get My Advanced Open Water?

With just another 2 days of training, you can get your Advanced and that would give you up to 30 metres of depth.

Right now, I’m a bit ‘watered-out’ and 20m is plenty deep to see pretty fish and coral.

When night dives and ship wreaks call my name, I’ll look into the Advanced course. 

At that time, I would LOVE for Beth to be my instructor again. 

Next time I dive:

The ideal conditions for me would be:

  • a CALM surface – tiny, baby waves or no waves at all 
  • HIGH visibility – we only had about 5-8 meters, but it felt like a lot less 
  • Above 30C water temperature – even though it was 28-29C, I think warmer would be nicer
  • Using my own mask &
  • Wearing a long sleeve/pant wet suit – I don’t want weird tan lines again and it can act as a protective layer to my skin

I really want to try drift diving in Indonesia. I’m told that you just let the current carry you, you don’t even need to swim. 

Known as the lazy person’s sport, I’m ready to actually be lazy next time I dive. 

Just like what I feel about getting a personal trainer, if you’re physically able and like water sports, you should absolutely get your Open Water! 

It’s like a mental strength test – time to show yourself what you’re made of. 

Hope this helped you in your decision to get your Open Water (or not).

If you already got yours or a higher level, let me know where and how it went! 

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