with Hydronauts


Invented by cave divers, Sidemount diving has risen to prominence in the dive community over the past decade. The usefulness of this configuration extends beyond overhead and technical diving to the recreational realm.

Sidemount diving consists of using specialized BCDs to attach cylinders on one’s side, rather than on the back. The benefits of diving with a Sidemount configuration include increased gas supply, gas redundancy, increased streamlining, ease of attaining perfect in-water trim body positioning, flexibility with equipment transportation, and comfort in the water.

Hydronauts has some of Koh Tao’s most experienced sidemount instructors who truly take the time to ensure that you will excel in this configuration.

15,000 THB



Must be medically fit to dive.

Must be at least 15 years old.

Sidemount diving does not have any prerequisites –but we recommend that you be certified as an Open Water diver. 

The Sidemount course is designed to be combined with almost any course. Consider combining it with: 

 Explorer 30, Advanced 35, Deep 40, and/or Nitrox courses. 

The prerequisites of these other courses apply underwater in an Open Water environment.

Step 1 -
Online Study

Contact us to unlock your e-learning materials
 Your training starts online where you will access all your RAID training manuals and quizzes.

Step 2 - Theory & Workshops

 On arrival, you’ll meet your instructor who will review your pre-completed e-learning with you. Your instructor will conduct workshops on equipment systems, set-up and configurations to help you get the most out of your learning experience.

Step 3 - Pool Training

Your confined water or pool dives will begin by improving your awareness of the Sidemount set-up. Fine tuning your weighting distribution and trim is paramount to comfort and safety. You will practice valve shut off drills, self-rescue, and air sharing skills.

Why Choose Hydronauts?​

RAID Instructors​

Our experienced instructors are hand-picked, highly trained, and passionate about scuba diving. We tailor each course and dive to your unique needs.

Beachfront Diving Resort​

Southwestern-facing diving resort including a hotel, purpose-built training pool, restaurant, dive boat, and beach bar. We offer diving & accommodation packages for every budget.

Guaranteed Small Groups

We guarantee small groups of no more than four students to an instructor or dive guide so that you get the individual attention you deserve.

State-of-the-Art Equipment

We choose to dive and teach in Backplate & Wing BCD with a Long-hose, Short-hose regulator configuration favored by technical divers.

Dive Anywhere in the World

Upon completion of your RAID scuba diving course, you will be issued with an e-certification card that recognizes you as an internationally certified scuba diver.

Low Carbon Footprint

We make every effort to reduce our footprint and use of paper and plastic. All our course materials are hosted online giving you access for life.

Reserve your space now


You must wait 18 hours after your last dive before flying in an aircraft.

Need a place to stay? We’re a beachfront diving resort! We offer rooms from single-gender to mixed dorms, queen rooms, family rooms, and bungalows for weekly or monthly rent! You can book a room here

Please stay hydrated – drink lots of water before and after your dives.

Bring sunscreen (preferably reef safe!)


Have another questions? Reach out to us!

Yes! We are a 3-star beachfront resort! We have dorm rooms starting at 300 THB and private accommodation starting at 600 THB. Message us and ask about our diving and accommodation packages! 

Yes! You can begin your reading and quizzes before you get here but you’ll need to complete the workshops and exams with your instructor when you arrive. Contact us now to get started! 

Explorer 30 or Advanced 35 are the next courses we recommend after your Open Water 20 Course. These courses will get you to improve your buoyancy, advance your understanding of dive planning, and get you diving on shipwrecks, deep sites, and maybe even diving at night! Get in touch with us to learn more! 

Yes. All the answers are in the manuals for you to review anytime. Our approach to education is for students to comprehend and practice through repetition rather than focusing on textbook memorization. This ensures that your actions–underwater especially–are informed and contextual rather than rote and textbook. 

Yes! Check our Try Dive page or get in touch with us to learn more! We can’t wait to show you the underwater world and teach you to defy gravity!