1. Always Dive with a Buddy
A good buddy provides another set of eyes, another set of hands, and an additional source of assistance when something goes wrong. Stay close enough to help one another, communicate regularly, and understand each other's equipment and procedures. Diving with a buddy only provides meaningful protection when you're actually diving together.
2. Always Follow a Pre-Dive Checklist
Before every dive, work through a consistent checklist to verify that you and your equipment are ready. Check your breathing gas, cylinder valves, regulators, buoyancy equipment, weights, instruments, and anything else required for the dive. Don't rely on memory or assume everything is fine because it worked on your previous dive.
A checklist helps catch the ordinary mistakes that occur when you're distracted, rushed, or overly familiar with your equipment. But it only works if you actually follow it. See Pre-Dive Checks.
3. Check Your Equipment Again Before Descending
Once you're in the water, confirm that your equipment is functioning properly before descending. Breathe from your regulator, verify that your BCD inflates and vents, and have your buddy look for bubbles escaping from hoses, valves, or cylinder connections. Equipment can shift or become disconnected during entry, so this final check catches problems that may not have been apparent beforehand.
Learn more about performing a proper bubble check.
4. Plan Your Dive, Dive Your Plan
Agree on your intended depth, time, route, gas reserves, and conditions for ending the dive before entering the water. Discuss what you'll do if something changes, including unexpected currents, deteriorating visibility, or buddy separation. Both divers should understand the plan and their responsibilities.
A structured approach such as GUE EDGE can help organize the discussion. The specific method matters less than having a clear, realistic plan that everyone understands and follows.
5. Use Proper Weighting and a Balanced Rig
Carry only the weight you need, accounting for changes in cylinder buoyancy as gas is consumed. Excessive weight complicates buoyancy control and requires additional gas in your BCD to compensate. Your equipment should also be configured so that you can maintain buoyancy and manage an ascent safely, including foreseeable equipment problems.
Understanding the concept of a balanced rig is particularly useful, regardless of whether you dive a conventional BCD or a backplate-and-wing system.
6. Secure Loose Equipment
Keep hoses, gauges, lights, and accessories secured rather than dangling beneath you. Loose equipment creates snag hazards, can damage the environment, and makes it harder to locate or operate something when you need it.
Arrange your equipment consistently, with frequently used items accessible and everything else properly stowed. You should know where each piece of equipment is and be able to reach it without searching.
7. Monitor Your Gas Supply Regularly
Running out of breathing gas should be an avoidable emergency. Know how much gas you have, how much you need to complete the dive, and what reserve you've established for unexpected problems.
Monitor your supply throughout the dive and begin your return or ascent according to your plan, rather than waiting for an arbitrary cylinder pressure. Proper recreational gas planning should account for both divers and the requirements of the dive.
8. Ascend Slower Than You Think
Most divers ascend faster than they need to. Make your ascent deliberate and controlled, slowing further as you approach the surface. Monitor your dive computer, complete your safety stop, and pay particular attention to the final ascent from your safety stop to the surface. Never treat your computer's maximum permitted ascent rate as a target.
9. Get Proper Training for Advanced Diving
Don't undertake dives that require skills or procedures you haven't been trained to perform. Greater depths, planned decompression, mixed gases, and overhead environments introduce additional risks that ordinary recreational training doesn't adequately address.
Seek appropriate instruction before attempting these activities, and develop proficiency in the required skills before relying on them in demanding conditions. Specialized equipment or additional certifications aren't substitutes for demonstrated competence.
10. Remember the Humans
Diving involves people, and people make mistakes. We get distracted, become tired, overlook obvious problems, and occasionally convince ourselves that everything is fine when it isn't.
Use checklists, verify important information, communicate clearly, and pay attention when something doesn't seem right. Good diving practices should account for normal human limitations rather than assume everyone will perform perfectly.
For more on recognizing and managing these vulnerabilities, see Human Factors in Diving.