A snorkel is useful when you want to spend a meaningful amount of time swimming face-down at the surface without using gas from your cylinder. I normally swim on my back, where I can breathe atmospheric air without anything in my mouth, and I use my regulator when I need to remain face-down. That leaves very little work for a snorkel to do.

Why Snorkels Became Standard Scuba Equipment

Snorkels make sense in entry-level training because new divers spend considerable time at the surface and need a way to practice face-down swimming without using cylinder gas. That training context helped establish the snorkel as part of the traditional recreational scuba kit.

The usefulness becomes less obvious after certification. Boat divers may spend almost no time swimming at the surface. Shore divers may have longer swims, but those do not necessarily need to be done face-down. Carrying a snorkel simply because it appeared on an original equipment checklist is different from carrying one because the planned dive gives it a job.

I Prefer Swimming on My Back

For almost every surface swim, I inflate my BCD enough to float comfortably, roll onto my back, and kick. My face is out of the water, breathing is unrestricted, and I use no cylinder gas. In calm water I have been comfortable enough in that position to stare at the sky and almost fall asleep.

The compromise is navigation. I have to check my heading periodically because I am not continuously looking where I am going. For a long, uncomplicated swim, I find that minor compared with spending the entire distance face-down. Surface Swimming Techniques covers the technique in more detail.

When I do need continuous visibility ahead or below, I use my regulator. That usually happens for relatively short periods while approaching a descent point, following a shallow feature, or moving toward a boat or exit.

Saving Gas Is Not Much of an Argument

A snorkel does conserve cylinder gas while you are breathing through it. The amount involved during a normal recreational surface swim is small.

A typical aluminum 80 contains about 77.4 cubic feet of gas at 3,000 psi. At a light-to-moderate surface breathing rate of roughly 0.7 cubic feet per minute, the regulator uses about 27 psi per minute.

A three-minute surface swim uses approximately:

\[ 27.4\ \text{psi/min} \times 3\ \text{min} \approx 82\ \text{psi} \]

A five-minute swim uses approximately:

\[ 27.4\ \text{psi/min} \times 5\ \text{min} \approx 137\ \text{psi} \]

I consider that negligible in an ordinary recreational dive. If the swim becomes long enough for gas conservation to matter, swimming on my back eliminates cylinder use entirely.

Why I Do Not Want One Attached to My Mask

A rigid snorkel sits beside the head for the entire dive even though it may only be useful for a few minutes at the surface. It can catch on line, vegetation, hoses, or other equipment, and anything that strikes or pulls the snorkel transfers that force to the mask strap. It can also move in current and tug at a mask that otherwise fits perfectly well.

None of those disadvantages is enormous by itself. The problem is that I am accepting them for equipment I almost never use.

I prefer scuba equipment to earn its place in the configuration. A snorkel mounted to my mask does not.

A folding snorkel carried in a pocket removes most of those objections. If I were required to carry one, that is probably how I would do it. It stays out of the way during the dive and is available at the surface if needed.

When a Snorkel Makes Sense

A diver who genuinely prefers long face-down surface swims has a reason to carry one. So does someone who intends to snorkel during surface intervals on a warm-water trip. A class, operator, or local rule may also require one.

Those are specific uses rather than evidence that every recreational diver needs a snorkel on every dive.

If you choose to carry one, it should fit without pulling on the mask, and you should be comfortable clearing it after flooding and switching back to the regulator when conditions deteriorate. Using a Snorkel at the Surface covers those skills.

Do You Need One?

I do not think most scuba divers need a snorkel by default.

Swimming on my back handles long surface distances without using cylinder gas, while the regulator handles the shorter periods when I want to remain face-down. A snorkel makes sense when the dive creates a specific use for one, but I would rather choose equipment around the diving I actually expect to do than carry something simply because scuba divers traditionally have.