Get SCUBA Certified

SCUBA certification is not a fun extracurricular on the astronaut path. It is a prerequisite. NASA expects astronaut candidates to be comfortable, competent, and calm in water — and the training to prove it starts the day you arrive in Houston.

Here is the reality that most people do not know: astronauts spend far more time underwater than they ever spend in space. For every hour of extravehicular activity (EVA) — a spacewalk — NASA’s astronauts log between 7 and 10 hours of underwater training in the Neutral Buoyancy Laboratory at Johnson Space Center. The NBL is a 6.2-million-gallon pool, 202 feet long, 102 feet wide, and 40 feet deep. It contains full-scale mockups of the International Space Station modules and external structures. When astronauts train for a spacewalk, they are wearing a 300-pound spacesuit underwater for six hours straight.

If you are not comfortable in water, you will not survive astronaut training. Period. And if you arrive in Houston already SCUBA certified with hundreds of logged dives, you start from a position of strength that most candidates do not have.

This is one of the simplest, most concrete steps you can take right now to build toward an astronaut career. You do not need a PhD. You do not need a pilot’s license. You need a swimsuit, a certification course, and the willingness to spend time in the water.

The Neutral Buoyancy Laboratory: Why Water Comfort Matters

The NBL is the primary training facility for EVA procedures. Underwater, with carefully calibrated buoyancy, astronauts experience something approximating the weightlessness of space. The physics are not identical — water creates drag that space does not — but the NBL remains the best ground-based analog for EVA work.

A typical EVA training run in the NBL works like this: the astronaut is suited up in a modified spacesuit (the Extravehicular Mobility Unit, or EMU), lowered into the pool by crane, and weighted to achieve neutral buoyancy. Then they practice the specific tasks planned for an upcoming spacewalk — installing hardware, routing cables, operating tools — while safety divers surround them.

These sessions last up to six hours. You are breathing compressed air, communicating through a microphone, working with tools that are deliberately difficult to grip through pressurized gloves, and managing your body position in three dimensions. If water makes you anxious, every one of those hours is a fight against panic instead of a productive training session.

Astronauts who arrive at NASA already comfortable underwater — who have spent time at depth, who understand buoyancy control, who have managed equipment malfunctions in open water — have a significant advantage in NBL training. They can focus on the task, not the environment.

NEEMO: The Underwater Research Station

NASA’s NEEMO (NASA Extreme Environment Mission Operations) program takes this even further. NEEMO sends crews of astronauts, engineers, and scientists to live and work in the Aquarius Reef Base, an underwater habitat off the coast of Key Largo, Florida, at a depth of about 62 feet. Missions last up to three weeks.

NEEMO missions simulate the isolation, confined quarters, communication delays, and EVA operations of deep space missions. Crew members conduct real marine science while testing space exploration procedures and hardware. Several NEEMO participants have gone on to fly in space — it is considered a direct analog for lunar and Mars surface operations.

You do not need to be a NEEMO participant right now. But if you want to eventually be the kind of candidate they select, start with SCUBA certification and build from there.

Your SCUBA Certification Path

SCUBA certification follows a clear progression. Here is the path, starting from zero experience:

Step 1: PADI Open Water Diver

This is your entry point. The PADI Open Water Diver certification is the most widely recognized recreational diving credential in the world, accepted in over 186 countries. It qualifies you to dive independently (with a buddy) to a maximum depth of 60 feet (18 meters).

What the course covers:

• Physics of diving: pressure, buoyancy, gas laws
• Equipment: regulator, BCD (buoyancy control device), dive computer, wetsuit, mask, fins
• Dive planning: air management, depth limits, surface intervals, no-decompression limits
• Safety procedures: buddy checks, controlled ascents, emergency weight drops
• Underwater skills: mask clearing, regulator recovery, buoyancy control, navigation

Course structure:

• Knowledge development: 5 sections of self-study (online through PADI eLearning or in-classroom)
• Confined water dives: 5 pool sessions where you practice skills in a controlled environment
• Open water dives: 4 dives in a lake, quarry, or ocean, demonstrating all skills at depth

Timeline: 3 to 5 days for the in-person portion (pool and open water dives). The online knowledge portion can be completed at your own pace before the pool sessions. Most students complete the full course in one long weekend or spread it over two weekends.

Cost: $300 to $500 at most PADI dive centers. This typically includes instruction, pool/open water dive fees, and equipment rental. Some shops charge separately for equipment rental, so confirm what is included. The PADI eLearning course is about $190 on its own; many dive shops bundle it into the total price.

Age requirement: PADI Open Water certification is available at age 15+. Students ages 10-14 can earn a Junior Open Water Diver certification with slightly more restrictive depth and supervision requirements.

How to find a dive shop: Use the PADI Dive Shop Locator at padi.com. Enter your zip code and filter by “Open Water Diver” courses. Read reviews. A good dive shop has experienced instructors who are patient with beginners and maintain equipment meticulously. Red flags are the same as in any training environment: pressure to buy expensive gear before you are certified, disorganized scheduling, and instructors who seem rushed.

Step 2: PADI Advanced Open Water Diver

After 10-15 logged dives, take the Advanced Open Water course. This is not an “advanced” course in the sense of being difficult — it is an introduction to five specialty diving areas. You choose from options like deep diving (100 feet/30 meters), underwater navigation, night diving, search and recovery, and peak performance buoyancy.

Cost: $250 to $400. Requires 5 adventure dives over 2-3 days.

Why it matters: Advanced Open Water introduces you to deeper depths, more challenging conditions, and the kind of task-focused underwater work that mirrors NBL operations. Navigation and buoyancy control are directly relevant to EVA training.

Step 3: PADI Rescue Diver

This is where SCUBA training starts to look like astronaut training. The Rescue Diver course teaches you to manage emergencies — not just your own, but other divers’. You learn to recognize and respond to distressed divers, manage unconscious divers at the surface and underwater, handle missing diver scenarios, and coordinate emergency evacuations.

Prerequisites: Advanced Open Water certification plus a current Emergency First Response (EFR) or equivalent first aid/CPR certification.

Cost: $300 to $500. Typically 3-4 days of training.

Why it matters: NASA wants astronauts who stay calm in emergencies and take care of their teammates. Rescue Diver training builds exactly those skills in a high-stress aquatic environment. It also requires you to be fit enough to tow another diver, manage equipment under duress, and make decisions when things go wrong. This is the certification that moves you from recreational diver to someone with genuine water competency.

Step 4: PADI Divemaster (Optional but Valuable)

Divemaster is the first professional-level PADI certification. You learn to lead certified divers, assist with training courses, and manage dive operations. Requirements include 60 logged dives, mastery of all rescue skills, stamina tests (400-meter swim, 800-meter snorkel swim, 100-meter tired diver tow, 15-minute treading water), and an extensive knowledge exam.

Cost: $500 to $1,000 plus your time assisting with courses.

Why it matters for the astronaut path: Divemaster is leadership in a technical, safety-critical environment. That is precisely what NASA evaluates during astronaut selection. Your Divemaster certification tells the selection board that you do not just participate in water operations — you lead them.

Building Genuine Water Comfort

Certification is the starting point, not the destination. NASA’s astronaut training pipeline will test your water comfort in ways that go beyond recreational diving. Here is how to build the kind of deep, reflexive comfort that serves you in the NBL:

Dive regularly. Certification means nothing if you dive twice a year. Aim for at least 2-4 dives per month once you are certified. Log every dive. Track your air consumption, depth, and conditions. Over time, you want to accumulate 100+ logged dives before you even apply to NASA.

Dive in varied conditions. Do not just dive warm, clear Caribbean water. Dive in cold water, low visibility, current, and night conditions. The NBL is a controlled environment, but the skill sets built in challenging open water translate directly.

Practice task loading. During recreational dives, give yourself tasks: underwater photography, navigation challenges, search patterns. The goal is to be comfortable doing complex work while managing your buoyancy, air supply, and situational awareness simultaneously. This is the closest recreational analog to EVA training.

Swim regularly. Separate from diving, maintain a swimming routine. NASA’s astronaut candidate training includes a military-style swim test: candidates must swim 3 lengths of a 25-meter pool without stopping (75 meters), then swim 3 lengths in a flight suit and tennis shoes. They must also tread water continuously for 10 minutes. If you cannot comfortably swim 300 meters and tread water for 10 minutes today, start building toward that.

Consider freediving. Breath-hold diving (freediving) builds a different kind of water comfort — the ability to be submerged without breathing apparatus, manage the mammalian dive reflex, and stay calm under oxygen deprivation. A basic freediving course ($200-$400) is a valuable supplement. Several astronauts have freediving experience.

AI in the Context of Spacewalks

This might seem like a stretch, but there is a direct connection between AI and the SCUBA training you are starting now.

NASA’s next-generation spacesuit — the xEMU (Exploration Extravehicular Mobility Unit), being developed under the Axiom Space contract for the Artemis program — incorporates AI-integrated health monitoring systems. These systems track astronaut vital signs in real time: heart rate, oxygen consumption, CO2 levels, core body temperature, and metabolic rate. AI algorithms analyze these data streams to predict fatigue, detect anomalies, and alert both the astronaut and Mission Control to potential problems before they become emergencies.

EVA planning is also becoming increasingly AI-augmented. Mission planners use machine learning models to optimize EVA timelines, predict tool usage patterns, and simulate contingency scenarios. The astronauts who conduct these EVAs need to understand what the AI is telling them, when to trust its recommendations, and when to override.

When you are in the NBL in a spacesuit, managing an AI health monitoring display while routing cables on a mockup of the ISS — that is the future of EVA operations. Your SCUBA training today builds the water comfort foundation. Your AI/ML studies (see Step 1) build the computational literacy. Together, they prepare you for a spacewalk environment that is fundamentally different from anything the Apollo or Shuttle-era astronauts experienced.

Cost and Timeline Summary

Total investment to Rescue Diver: roughly $925-$1,550 and 10-14 days of training. Spread over one to two years, this is manageable for most families — less than the cost of a single semester of club sports at many high schools.

Your Action Plan

This month:

• Research PADI dive shops within driving distance of your home using the PADI Dive Shop Locator.
• If you are not already a confident swimmer, start a swimming routine: 30 minutes, 3 times per week. Work toward swimming 300 meters continuously and treading water for 10 minutes.
• Budget and plan for your Open Water course. Many dive shops offer payment plans.

Within 3 months:

• Complete your PADI Open Water Diver certification.
• Log your first 5-10 open water dives after certification. Many dive shops organize group dive trips that are inexpensive and social.

Within 6 months:

• Complete your Advanced Open Water certification.
• Begin your Emergency First Response (CPR/First Aid) certification.
• Accumulate 20+ logged dives.

Within 12-18 months:

• Complete your Rescue Diver certification.
• Have 50+ logged dives in varied conditions.
• Begin evaluating whether Divemaster is a good fit for your schedule and goals.

Ongoing:

• Maintain a regular dive and swim schedule.
• Track your dives in a logbook or digital app (PADI App, Subsurface, MacDive).
• Seek out challenging dive conditions that build genuine comfort, not just certifications.

The astronauts who thrive in the NBL are not the ones who got their Open Water card and stopped. They are the ones who fell in love with being underwater and kept going. Get certified, then keep diving. The water is where the work happens.