The heat of mid-summer is officially upon us. You have two options: sit in the air conditioning, staring longingly out the window at unrealized dreams being melted away by the hot summer sun, or you can strap a tank of air to your back and dive deeply enough into the water to escape the scorching heat. That’s an easy choice for an Adrenalist.

Scuba diving, however, isn’t as simple as slipping into a wetsuit and using an air tank to breathe underwater. Climate, local wildlife, the effects of compressed atmosphere on your body, even basic movement all require special training and consideration. You’re preparing yourself to enter an environment that is hostile to you in every fundamental way.

The tradeoff is an opportunity to see wonders that few will ever behold, but you’ve got to prepare.

Here is your scuba diving starter guide.

Certification

Scuba is derived from the acronym SCUBA, or Self-Contained Underwater Breathing Apparatus. If you’re a person living in the modern-day world then you can probably call up a mental image easily enough: wetsuit-encased diver with air tank on back and breathing hose leading to mouth. Your first step to getting there yourself is certification.

There’s no centralized agency for getting your diver cert and training squared away. You’ll have to choose one from a larger pool. Most beachside vacation resorts also offer some sort of scuba training program. While you can certainly track down a more local solution, there’s something to be said for using your poolside lounging time to prepare for your certification tests.

Since there’s no centralized program, training and certification mostly boils down to common sense. There’s technically nothing stopping you from going out and buying all of the necessary gear, then running off into the ocean to try it out. It’s not recommended though. All goes back to the whole “hostile environment on all sides” thing.

The three most well-known scuba organizations in the United States are the National Association of Underwater Instructors (NAUI), the Professional Diving Instructors Corporation (PDIC), and the Professional Association of Diving Instructors (PADI). All of them offer the full suite of resources you’ll need to get started, from training course search features to gear and dive recommendations. There are even a few eCourses available, though you’ll eventually need to strap on a tank and spend some time with an actual instructor.

Start out with beginner courses, especially if you’re not already used to spending lots of time in the water. Learning simple things like how to swim and how to more effectively hold your breath underwater are vitally important, so start there if you need to. Once you’ve got the fundamentals taken care of, it’ll be a lot easier to move onto the more dive training-specific lessons.

The Science of Scuba

Before we go any further, just know: this is in no way a substitute for the training that you would receive from a proper dive program. It’s helpful to understand concepts like how breathing apparatuses work and what the physical conditions are like underwater, but nothing will prepare you as well as an actual certification course will, especially if said course includes actual dive time with an experienced diver.

There are two basic types of breathing apparatus that are commonly used by scuba divers. The more common of the two is the single-hose open-circuit regulator. It’s a two-stage diving regulator with stops at the tank on your back and your mouthpiece to manage the flow of air. The two stages help to ensure that you’re receiving air at the right pressure level. Exhalations are released directly into the water, which is why you’ll often see a lot of bubbles coming from divers in video footage.

The less common apparatus is defined as a rebreather. Instead of venting out exhaled gas, the rebreather works by recycling your exhalations, resulting in the release of few or no bubbles. They’re mostly used when it’s important to maintain a low-profile, such as with underwater photography. Rebreathers are expensive and require special training, and as such they’re not nearly as common. For the most part, you can expect to encounter open-circuit regulated breathing apparatuses.

Underwater diving affects your vision, particularly when you’re in a saltwater environment. A diving mask of some kind will correct this to a limited degree, but objects will nonetheless appear to be both larger and closer than they actually are. Learning how to adjust your hand-eye coordination is a big part of scuba training. You’ll also need the right kind of mask; swimming goggles won’t cut it, since divers must periodically exhale through the nose during a descent in order to equalize the pressure inside the mask with the surrounding water.

The changing pressure of the surrounding environment is perhaps one of the biggest safety concerns for divers. Ascend or descend too quickly, and you risk suffering the effects of a barotrauma injury. This can mean death or extended periods of post-dive time in a decompression chamber in extreme scenarios. Avoid barotrauma by taking your time when moving to a different depth, using specialized gear like an inflatable drysuit and performing simple pressure-equalizing exercises like exhaling through your nose or clearing out your ears (much like you would on an airplane).

Gearing Up

When it comes to scuba gear, there’s really no”right” or “best” option. What you use is more geared around what fits your level of training and what feels comfortable to you on a personal level. Let’s focus on what’s most common for recreational diving.

Think of recreational diving as the natural evolution of snorkeling. The latter activity is great for shallow-water exploration, but it’s inherently limited due to the snorkel mask’s need to be at or close to the water’s surface. Scuba diving equipment, even for recreational practitioners, is a lot more elaborate. You’ll need a suit, a breathing apparatus equipped with pressure regulators, a mask and a dive computer. Fins for your feet are helpful as well, for getting around more easily underwater.

For recreational diving, don’t expect to ever explore much deeper than 130 feet or so. The risks associated with diving become much more pressing at greater depths. That’s the realm of professional diving, and it’s also where you start to see gear like rebreathers become more common.

Expect to spend around $1,000 to completely gear up with your own scuba equipment. Package deals can be found for as little as $600-700, but they won’t always come with every piece that you need. Most packages set you up with a breathing apparatus and related technologies, but pieces like the suit (wet or dry), fins and mask are typically sold separately.

You’ll find any number of stores online catering to recreational and professional divers, but newcomers that want to spend money on their own gear will be best off exploring the websites of one of the larger scuba organizations. In reality, rental is the most cost-effective option. If you intend to dive very regularly, buying your gear is definitely an option to consider. Otherwise, you’ll often find that most resorts with some sort of scuba training program will also offer you the option of renting gear and heading out with a group for some dive time.