SSI Open Water vs Advanced Adventurer: Which Course Should You Do in Koh Tao?

A version of this question lands in my WhatsApp messages every week: "Should I do Open Water or Advanced? Or both?" The answer depends entirely on where you're starting from and what you want to be able to do after you leave Koh Tao. Let me give you the full picture.

I've taught both courses hundreds of times at Carabao Diving. I've seen students skip Open Water and regret it, I've seen experienced divers finally do their Advanced and wonder why they waited so long, and I've seen plenty of people do both back-to-back and leave the island genuinely transformed as divers. The right answer is not the same for everyone — but it's always one of the options below.

What Each Course Actually Covers

SSI Open Water Diver

The Open Water course is your entry point into recreational scuba diving. It certifies you to dive independently (with a buddy) to a maximum depth of 18 metres, anywhere in the world. The course is 3–4 days, typically 4 at Carabao. You start with theory — five knowledge development modules covering dive physics, equipment, dive planning, and underwater safety — followed by confined water sessions in the shallows, then four open water dives on real reef sites. By the end, you're a certified diver.

The confined water sessions are where most of the skill work happens: mask clearing, regulator recovery, buoyancy control, controlled ascents, and emergency procedures. These aren't arbitrary exercises — they're the skills that make the difference when something minor goes wrong underwater. We take them seriously, and we don't rush students through them.

SSI Advanced Adventurer

The Advanced Adventurer course is for already-certified divers who want to extend their depth limit to 30 metres and build specific skills. There are no pool sessions — it's five adventure dives in open water, each focusing on a different discipline. Two are mandatory: Deep Diving (taking you to 30m) and Navigation. The remaining three are chosen from a menu of specialties: Peak Performance Buoyancy, Wreck Diving, Night Diving, Drift Diving, Fish Identification, and others.

The course typically takes 2 days. You'll do two dives per day, with a briefing before each and a debrief after. The deep dive is often the one students find most significant — 30 metres is a different world from 18m, and the physical sensations (increased pressure, narcosis at depth) are tangible.

Side-by-Side Comparison

Who Should Do Which Course?

If You've Never Dived Before

Start with Open Water. Full stop. There is no shortcut to the foundational skills — buoyancy, air management, buddy procedures, emergency response. Every advanced skill in the Advanced course assumes you have these dialled in. Rushing into Advanced without an Open Water foundation is asking for a stressful experience underwater.

If You're Already Open Water Certified

The Advanced course opens up a significant portion of Koh Tao's best dive sites — Chumphon Pinnacle, Southwest Pinnacle, the HTMS Sattakut wreck at depth, and Sail Rock properly. If you're already certified and planning more than just a few fun dives, the Advanced course is genuinely worth the time. Two days, five dives, and you come out a meaningfully more capable diver with 30m access.

If You Want to Do Both

Doing both courses back-to-back is probably the most efficient way to make a Koh Tao dive trip count. The combined course takes approximately 6–7 days — Open Water first (4 days), then Advanced straight after (2 days) without a break. You go from zero diving experience to 30m Advanced-certified in one trip. We offer a discount when you book both courses together.

What Actually Changes After Your Advanced?

Depth access is the obvious one — 30m vs 18m opens up the majority of serious dive sites globally. But there are less obvious changes too. Your buoyancy improves measurably after five guided dives focused specifically on trim and control. Your air consumption drops as you relax and breathe more efficiently. Your confidence reading a dive site — understanding current, planning your route, navigating without GPS — is genuinely different after the navigation dive.

There's also a practical industry reality: many dive operators around the world, especially for liveaboards and technical diving entry programmes, require Advanced certification to join. An Advanced card broadens what's available to you as a travelling diver significantly.

One Last Thing: Don't Rush

The most common piece of advice I give is this: do Open Water, take a few fun dives to enjoy what you've just learned, and then decide about Advanced. The certifications are tools — they unlock access and build skills. But if you rush through both courses in a week just to have the card and never actually savour any of the diving, you've missed the point entirely.