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Top 10 Scuba Diving Rules and Safety Measures

From making a safety stop to controlling your ascent rate, these are the most basic safety measures of scuba diving.
By Alexandra Gillespie | Authored On October 18, 2006
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Top 10 Scuba Diving Rules and Safety Measures

Recreational diving is still a relatively young sport. Created in the 1950s, it gained acceptance in the '60s and '70s, boomed in the '80s and took great technological leaps in the '90s. If you've been diving for decades, there's a good chance that not everything you learned in your open-water class still applies. New research and equipment have made diving safer and more enjoyable than ever—if you know the rules. We thought we'd take a look at some of them and see how they've evolved.

1. Reverse Dive Profiles Are OK

New Rule
It is permissible to dive deeper on your second dive than on your first, and to dive deeper on the later part of a dive than on the early part.

Old Rule
Most divers have been taught to go to their greatest planned depth early in the dive and then gradually work upward in a regular "stair-step" pattern. Similarly, they've been told to make the deepest dive of the day the first one. The rationale was that the shallower depths later provided decompression for the preceding greater depths.

Reason for the Change
Dive computers. Because computers can track your depth and time constantly and are pretty good at math, it's possible to know your nitrogen exposure accurately regardless of your profile. Tables, by contrast, can account for only your greatest depth, and this crude approximation of nitrogen exposure still mandates a conservative approach.

Exceptions to the Rule
Obviously, divers using only tables must still follow the old rules. And even when using a computer, it's still smart to dive deeper first. Ascending profiles give you more bottom time and a greater margin of safety against DCS.

2. Lower Minimum Age

New Rule
The Recreational Scuba Training Council, which sets many industry standards, dropped its minimum age requirement for junior certification near the end of 1999. As a result, PADI, SDI, SSI and NASDS (which has since merged with SSI) dropped their minimum age requirements for junior certification to 10. Ten-year-olds can get a PADI Junior Scuba Diver, and 8-year-olds can enjoy PADI's Bubblemaker and Seal Team programs, which are held in a pool in less than 6 feet of water. SSI has a pool-only "Scuba Ranger" program for 8- to 12-year-olds.

Old Rule
Minimum age for junior certification was 12. (Junior certification requires supervision by a fully certified adult.)

Reason for the Change
To promote the sport. Lots of divers have kids, and the growing popularity of resort diving meant a market for family dive vacations. "The future of diving will be determined by kids," says Bret Gilliam, president of SDI, the first agency to lower the age. "It's a great step forward to recognize the family unit as key to our sport's growth."

Exceptions to the Rule
It's still up to the instructor to decide whether a child is mature enough to dive. Being 10 does not create a right to be certified.

The new junior certifications typically have various restrictions. In PADI, kids are limited to 20 feet in confined water first, then 40 feet in open water. Juniors must be accompanied by an agency-affiliated instructor, a certified parent or another certified adult. Check specific agencies for their rules.

3. Universal Referrals

New Rule
Getting certified? Beginning in 1998, you could take classroom and pool sessions in your hometown from an instructor with Agency "A," then fly to warm water for open-water sessions under an instructor with Agency "B"— as long as the agencies had agreements to recognize each other's standards and instructors. This means you can choose from many more warm-water resorts for your open-water sessions.

Old Rule
Classroom, pool work and open-water dives all had to be with the same training agency. If you wanted to do the open-water dives in the tropics, you had to pick a resort with an instructor affiliated with the same agency.

Reason for the Change
Customer convenience. Smaller agencies with few instructors in place at resorts found it necessary to band together to offer greater options — especially when certification standards are virtually identical.

Exceptions to the Rule
It can be a matter of trust. Some students may not be comfortable "switching" instructors, and so may prefer making their open-water checkout dives with the same instructor who was with them the first time they took their first breath underwater in a pool.

4. Slower Ascent Rate

New Rule
Ascend no faster than 30 feet per minute — one foot every two seconds.

Old Rule
The usual rate was 60 feet per minute until the U.S. Navy adopted the 30-foot-per-minute rate in 1996 and training agencies followed suit.

Reason for the Change
Research. Navy studies found that a 30-foot-per-minute rate resulted in fewer cases of DCS than the older 60-foot-per-minute rate. A slow ascent is really a rolling decompression stop, allowing your body to flush out and exhale dissolved nitrogen before it forms bubbles.

Exceptions to the Rule
The 30-foot-per-minute rate may not always be practical for the whole ascent, especially when you are deep and low on air or approaching hypothermia. In that case a faster rate, up to 60 feet per minute, is acceptable, but for the final 60 feet of your ascent, you should slow to 30 feet per minute.

5. The Safety Stop

New Rule
Make a safety stop at the end of dives. That means you should pause at about 15 feet for a minimum of three to five minutes before your final ascent to the surface. Some experts recommend safety stops as long as 10 to 15 minutes under certain conditions.

Old Rule
Make a what? Safety stops were not taught prior to the mid-1980s.

Reason for the Change
More research. The new rule recognizes that all dives are decompression dives, and that DCS can and does occur even when you've stayed within so-called "no-decompression limits." Studies clearly show that pausing at about 15 feet allows you to offgas nitrogen before ascending through the zone of greatest pressure change, near the surface. Nitrogen that hasn't been eliminated can bubble out of tissues rapidly during the last part of the ascent, causing DCS.

There are other safety reasons for the stop. The air in your BC and the bubbles in your wetsuit also expand rapidly during the last 15 feet and may cause you to become significantly positive without realizing it. Stopping gives you a chance to adjust your buoyancy so you don't lose control of your ascent.

Safety stops also allow you to survey surface conditions and boat traffic before surfacing.

Exceptions to the Rule
You needn't stay at exactly 15 feet, especially if you're elbowing a crowd of other divers. Anywhere between 10 and 20 feet is fine. And although three to five minutes is a good minimum, longer, deeper dives call for longer safety stops.

6. Neutrally Buoyant Ascents

New Rule
Become neutrally buoyant before beginning your ascent and maintain neutral buoyancy throughout.

Old Rule
Dump all air so you are negative before beginning your ascent and fin upward against negative buoyancy.

Reason for the Change
The old rule was designed to prevent runaway ascents. But Navy studies revealed that the strain of finning hard while ascending sometimes causes divers to hold their breath. Also, it can lead to air trapping in the lungs. Both present embolism risks. The change also reflects greater confidence in modern BCs, particularly their dump valves.

Exceptions to the Rule
In an ascent from very shallow depths, say 30 feet or less, it's OK to fin up against slight negative buoyancy. The risk of losing control because of rapid buoyancy changes in your BC and exposure suit, and the low stress in finning such a short distance, makes this the better bet.

7. No More Buddy Breathing

New Rule
In a no-air emergency, depend on a redundant system or your buddy's octopus, or make an independent emergency ascent. Do not attempt to "buddy breathe" from a single regulator unless you and your buddy have practiced it.

Old Rule
Before octos, ponies and devices like the "Spare Air" were common, divers were taught to pass one regulator back and forth while making a slow ascent.

Reason for the Change
Safety. Experience showed that unless both buddies had practiced buddy breathing and were skilled at it, the attempt was likely to injure both divers, not just one.

Typically, buddy breathing divers become so absorbed in passing the regulator that they neglect to control their buoyancy, and a too-rapid ascent with embolism could result. Or the diver who has passed the regulator holds his breath instead of exhaling slowly, also an embolism risk.

If you are out of air and neither you nor your buddy has a backup system, your best move is to make an emergency swimming ascent: swimming to the surface while keeping your throat open by slowly exhaling.

8. The Buddy System

Every training agency is emphatic on the need to always dive with a buddy. Yet solo diving has long been common, particularly among underwater photographers. Experience, and incomplete statistics, don't indicate that solo diving is more dangerous than buddy diving, and some divers argue that solo diving is actually safer.

9. The Snorkel

Most of us were taught that a snorkel is mandatory gear on every dive, just like a pair of fins. But increasingly, divers are leaving the snorkel in the gear bag much of the time.

Why? They've come to the conclusion that a snorkel, when attached to your mask, is more often a hazard than a help. The long tube—dangling from its midpoint so the hook-like gizmos at the ends can wander around — is pretty effective at catching kelp, fishing line and camera straps. And, given the importance of your mask, your mask strap is about the worst place to mount it or anything else.

Many divers now save the snorkel for special occasions, like a long surface swim from their entry point to the dive site, and carry it in a pocket or strapped to their body.

10. The Dive Computer

The dive computer is probably the most important safety advance in the sport. Much more important than a snorkel, and arguably more important than an octopus, a dive computer is often considered mandatory equipment today. "Virtually all divers now use dive computers to make diving safer and more enjoyable. Why not establish that practice from the beginning?" says CEO Bret Gilliam. "Dive tables have simply been supplanted by advances in technology."

Divers photo at the top from Shutterstock. All other images by Bret Gilliam.

Two divers to predive safety check at the shore

A pre-dive safety check with your buddy is one of the basic steps you should take to improve your dive safety Flair

Diving has a great safety record when you dive responsibly, following the rules and regulations. That’s the whole reason they exist, after all — to keep you healthy and whole and ready to dive again the second you finish your surface interval. Whether you’re still learning to dive or have a lot of experience, implementing these ten safety precautions will reduce your risk when you're underwater.

1. Make a Safety Stop

When is a safety stop required? Divers should make a safety stop at the end of every dive at a depth of 15 feet for three to five minutes. Safety stop diving gives your body extra time to release excess nitrogen that builds up in your system during the dive. Deep technical dives commonly require deeper and longer decompression stops, but three to five minutes at 15 feet is standard for recreational dives within no stop dive limits.

2. Control Your Ascent Rate

You don’t want to rocket toward the surface for a few reasons. First, your body needs time to release dissolved nitrogen (hence your safety stop). Second, since air expands while rising through the water column rapidly, air expanding in your lungs as you ascend too quickly increases the risk of lung overexpansion injuries like air embolism. And, to control your ascent rate, control your ascent rate. That is, as air in your BCD, dry suit or wetsuit material expands, you become more buoyant and your ascent rate starts to accelerate. When you're ascending slowly, you can easily release air from your BCD/dry suit to keep your buoyancy and ascent rate under control. But if you ascend rapidly, it's harder to compensate fast enough, leading to a "snowball" effect of more increasing buoyancy and ascent speed. Learning how to ascend when scuba diving is one of the most important diving rules.

Want to be a safer diver? Become a Rescue Diver through PADI.

3. Keep Breathing

Continually breathing when submerged protects your lungs from lung overexpansion injuries. This is not important just during ascent, but throughout the entire dive. Not only does this reduce your risk in case you're ascending and don't realize it for some reason (rare, but it happens), but you're developing and maintaining the right habit.

4. Watch Your Gauges

Your gauges, or dive computer, constantly tell you important information like how deep you are, how long you’ve been down, how much air and no stop time you have left, which way is north and so on. Check these frequently to ensure you’re staying within your dive plan. Your air consumption especially can change not only from day-to-day, but within the dive depending depth, current, exertion, stress, body temperature and a host of other variables. Don't assume a certain fill will give you the same bottom time as a previous dive. Check your air levels often – every few minutes at the most – and turn the dive so you surface with at least 500 psi reserve.

##5. Stick with Your Buddy Diving is not a solo sport. “Buddy diving is a potentially life-saving practice for scuba divers,” according to DAN’s 2019 report on dive fatalities. “Properly implemented, it helps to prevent accidents and to avert bad outcomes of possible incidents. Buddy diving starts with sharing the dive plan, getting familiar with each other’s equipment, pre-dive buddy check, keeping an eye on each other during the dive, sticking to the plan, returning to the surface together, and conducting a post-dive debrief.” Statistics and research repeatedly support that the buddy system reduces risk.

6. Dive Within Your Training

With the exception of being under instruction with a professional instructor, never attempt a dive beyond your training, whether that’s visiting a wreck deeper than you’re certified to go or entering a cave system without taking a rigorous cave diving class. Training is vital to knowing how to handle different underwater environments. You can always take classes to advance your dive repertoire by learning the skills you need to penetrate a wreck, dive deep, explore a cave or dive high in the mountains, but don't try to learn them by yourself.

7. Dive Within Your Limits

Diving within your limits differs from diving within your training — personal limits change from day to day and year to year. You may be qualified to dive to 100 feet, but if you haven’t been diving in a few years, jumping straight into a dive that deep likely isn’t the best plan. Or, if not quite in your usual fitness due to not exercising for a few weeks, a rough shore dive with your local club may be off the table until you're back to yourself. You can always make it a goal to work up to your old limits, but, as life changes, respect your evolving boundaries.

8. Ensure You Equalize

Understanding how fast you can descend when scuba diving is crucial. Do not keep descending if your ears hurt. Diving isn't supposed to hurt, and doing so can cause serious and lasting damage, such as a ruptured drum or worse, which can permanently impair your hearing and exclude you from ever diving again. If you are struggling to equalize, signal your buddies (they can't know your ears hurt unless you tell them) rise slightly to a shallower depth and try again. If the pain continues, call the dive. Never, ever "force it."

9. Do a Pre-Dive Safety Check

Looking over your gear and buddy's gear (and having them do the same) is a good way to catch small issues that can become a big deal underwater. Look for open valves, full cylinders and properly secured releases, as well as things like loose weights that could fall and trigger a rapid ascent. Test breathe second stages and test inflators/deflators to be sure they're working properly. This process also acquaints you with your buddy’s gear in the event there is an emergency in which you need to assist.

10. Remember Your Objective

The primary objective of every dive is for everyone to come back safely. Do not let secondary objectives, like photographing a certain species or seeing a specific part of a wreck, get in the way of remembering your primary objective. Even if you "only need a minute" to get that "perfect shot" but you're at your turn pressure, skip the shot and turn the dive knowing you're fulfilling the dive's main objective.