The Importance of a Predive Safety Check

Checking your equipment and doing a buddy check, regardless of how many times you’ve dived with your gear or with the same buddy, can help prevent many of the common factors that lead to dive accidents. Photo by Stephen Frink

Certified divers learned to do predive safety checks during training, but do they perform one every time they dive? It is one of the easiest ways to prevent oversights, gear malfunctions and forgotten pieces of equipment. But predive safety checks often aren’t as thorough as they should be.

A predive safety check commonly follows the initials BWRAF, which stands for BCD, Weights, Releases, Air and Final check. Instructors use a variety of mnemonics to help students remember this list, including “Burger With Relish And Fries,” “Breathing Water Really Ain’t Fun” and “Begin With Review And Friend.” This content is similar to other predive check acronyms such as SEA BAG (Site survey, Emergency planning, Activity planning, Buoyancy, Air, and Gear and go) or ABC (Air, Buoyancy, and Clips and releases). Whichever way you remember to do a predive check, follow your training, and be systematic and consistent.

BCD: The first step is to confirm that your buoyancy compensator device will hold air. Check that the low-pressure inflator hose is snugly connected to the BCD and that the inflate and deflate buttons don’t stick to prevent buoyancy issues or uncontrolled ascents. Fill your BCD with air by testing the power-inflate and oral-inflate mechanisms. Pull each dump valve to ensure it is functioning correctly and not sticking open. Look at your buddy’s configuration and make sure that the toggle for the shoulder dump valve isn’t stuck under the shoulder strap, which could cause the diver to inadvertently pull open the dump valve, leading to buoyancy problems. Make sure the tank band securely holds the cylinder in place. If you are not familiar with your buddy’s BCD, learn about its inflation and deflation mechanisms in case of an emergency. 

Weights: This step is essential for ensuring the proper management of an emergency. You and your buddy should be familiar with each other’s weight configurations for ease of removal in the water if needed. Show your buddy where you keep weights — a belt, integrated pockets, trim pockets or ankle weights. If you use pockets, gently pull on them to ensure they are securely fastened. Make sure you have your weights before you enter the water.

Releases: This is arguably one of the most critical steps in the predive safety check. In case of emergency, you must know how to remove your buddy’s equipment. If you’ve never seen their setup, removing their BCD for the first time in the middle of an emergency could be difficult. Even if you are familiar with your buddy’s equipment, it is still a good idea to review it.

Show your buddy how to release your weights, especially if you use an integrated system. Your buddy should be prepared to manage the type of release you use, such as clips, rip cords, gravity release pouches or fabric fasteners. Discuss ways to release your equipment, including shoulder straps, chest strap and cummerbund. Make sure the tank band is tight enough to keep the cylinder in place. Review where you keep your octopus, gauges or other hoses — such as for a drysuit — and how to release them. 

Air: Make sure that your air is on all the way before entering the water. Many divers will glance at their submersible pressure gauge (SPG) to see if it reads full, but this does not guarantee that your tank valve is open. People sometimes turn on their air while setting up, check to make sure their cylinder is full, and then turn it off without releasing the pressure from their hoses by purging one of the regulators. A pressurized hose will make an SPG read as if your cylinder is full, but when you breathe all the air in the hose in one or two breaths, you could suddenly find yourself out of air. 

Most training agencies no longer recommend turning the handwheel a quarter-turn closed due to fatalities surrounding this practice. Novice divers and even some dive professionals can become confused about which direction to turn the handwheel, causing them to turn someone’s air only a quarter-turn on as opposed to a quarter-turn off. Modern cylinder valves do not succumb to wear and tear as older models did, so it is best to fully open your cylinder valve.

Another common mistake is not breathing from both the primary regulator and the octopus before you enter the water. There are several reasons to do so. The first is to ensure that they breathe easily, especially if you are using rented equipment. The second reason has to do with the inner workings of a second-stage regulator. Inside the regulator is a flexible diaphragm over a movable lever. When you breathe in, the suction effect flexes the diaphragm toward the lever to release air. When you exhale, the diaphragm flexes in the other direction, releasing the lever and stopping the air supply. The purge button is on top of this lever, so when you push the button you are manually pressing down on the lever. You want to make sure that the regulator will respond to your breath, not your touch. 

The third reason is to taste the air from your cylinder to ensure that it isn’t bad. Contaminants such as gas fumes or oil may have an oily taste, oily smell or bad odor. If you think you have bad air, alert the dive staff and do not use the cylinder.

When taking your first breath from each regulator, exhale first and then inhale. Debris or even critters could be hiding inside a regulator, and exhaling first will help ensure that they do not enter your mouth.

Before entering the water, check again that your air is fully on and consider taking a few deep breaths from your regulator while watching your SPG. If your air is completely on, the needle will hold steady. If your air is off but pressure is still in your hoses, the needle will drop dramatically with each breath. If your air is only partially on, the needle will bounce down and back up with each breath. 

Final check: Make sure you have all your miscellaneous equipment such as a mask, snorkel, fins, signaling devices and camera equipment ready. Streamline your equipment by securing any loose or dangling hoses or pieces of gear. Ensure that your computer is set to the correct gas mixture and paired to your cylinder if it is air-integrated. Defog your mask, and perform a head-to-toe check to make sure you do not forget anything else. Have your buddy check as well to make sure you didn’t miss anything. 

Complacency and skipping your predive safety check or buddy check are entirely preventable factors in dive accidents. Complete all your checks before every dive. 

© Alert Diver — Q3/Q4 2020