Diving with a Partner: Pre-dive checks are essential for dive safety

by B. N. Sullivan

I don't think there is a diver training program anywhere in the world that does not teach -- and emphasize -- the importance of the 'buddy system' for sport divers. The idea is to dive with a partner so that you can watch out for each other, and help each other if a problem arises.

In order for the buddy system to work optimally, dive partners need to know some things about each other's abilities, skill level, and equipment prior to entering the water. This is easier to do if you have one or more partners with whom you dive regularly, but it should be kept in mind regardless of whom you are paired with for a dive.

Dive BuddiesLet's take the case of diving with someone you don't know well or have just met. Don't be shy about asking the diver about the extent of his or her dive experience: what kind of training they have had, how often they dive, and how recently they have been in the water.

Certifications alone do not tell the whole story. A diver with a basic certification who does 50 dives a year may be a much more capable diver than, say, a certified rescue diver who only gets into the water a few times a year. Skills get rusty, and both competence and confidence erode with lack of practice.

The point of asking your prospective dive partner about experience and skills is not just a case of idle curiosity. You need to know the amount of monitoring your partner may need, and conversely, to what extent you can rely on that person to help you if you have a problem. If it sounds like there is a significant disparity between you and the other diver, it is wise to begin with very easy 'G-rated' dives with the person in order to minimize the risks while you get a fix on their skill level and comfort in the water.

Now, about equipment -- yours and your partner's. While all training agencies teach that you should dive with a buddy, some (I'm sorry to say) do not stress what is known as the pre-dive buddy check. The purpose of the buddy check is to ensure that each dive partner has all the essential equipment, that it is in good working order, and that each diver knows how to work the other's equipment.

The buddy check, plain and simple, is, "You show me yours and I'll show you mine."

We all use the same items of equipment when we dive, but there is a lot of variation among brands and models in regard to design and placement of controls. During the buddy check each diver shows the partner the location of every piece of critical gear, and demonstrates how it operates.

The idea is that if something untoward happens underwater, neither diver has to waste precious time fumbling about, trying to figure out how a partner's gear works. If I am your dive partner, I will want to know the following things -- at minimum -- about your equipment, and then I will show you the same things about mine.
  • Show me that the valve on your cylinder is turned on, and show me the display on the instrument you are using to gauge the remaining gas in your cylinder. I want to know how much air you have at the outset of the dive.
  • Show me your primary regulator, and demonstrate how the purge valve works. Then show me your back-up second stage - where it is stowed, and how it is released from where it is stowed. Then tell me whether you plan to hand off your primary or back-up second stage to me in an emergency.
  • Demonstrate your buoyancy compensating device (BCD). Show me how to inflate it, and also point out all the dump valves so I will know where they are.
  • Are you wearing a weight belt or are your weights integrated with your BCD? Do you have any extra weights in your pocket or in any unconventional places?
  • Show me the location of all the releases on your gear and how to work them -- especially for your weight system and BCD. Are they snaps, buckles, Velcro, pull-cords? I need to know what I am looking for in an emergency.
  • Show me your computer or other instruments. I don't want to have to figure out where to look on an unfamiliar display for critical information during an emergency.
Many divers are shy about asking a new dive partner to perform a buddy check and cross-check. Don't ever be shy about this. Be the one to initiate the buddy check; your partner will then doubtless go along.

If you are fortunate enough to have one or more regular dive partners, you probably are familiar with their equipment and know how it operates. But don't be complacent! Always check each other's gear configuration before entering the water. Weights in place? Air turned on? Instruments operating and displaying what you expect them to display?

I once had an experience that taught me not to ignore these things just because I was diving with someone I knew well. A frequent dive companion and I entered the water without doing a buddy check. We had been chatting and laughing while gearing up, creating just enough distraction so that we skipped cross-checking each other's equipment.

We were nearing 40 meters (about 130 ft), the deepest point of a our planned dive route, when I heard my companion shriek, right through her regulator. When I looked her way, I could see that she was alarmed. She turned the face of her air-integrated dive computer toward me, excitedly jabbing her finger at it. The display was blank -- no lights, no numerals, no data, nada!

We had to abort the dive then, of course. We stayed very close together as we gradually ascended during the hurried five minute swim back to our exit point. We had no idea how much air she had left, for openers. In fact, while we were swimming, it occurred to me that I did not even know how much air she had at the outset of the dive, since we had not done the buddy check and cross-check.

Once back on shore, we discovered that the problem was a dead battery in her computer. She admitted that she hadn't paid much attention to her computer display before the dive, since she 'knew' she had a full tank of air. For my part, I had never checked her equipment before the dive. I was annoyed with her, but I was really angry at myself. I knew better than that.

Had we done a routine check and cross-check, one of us might have noticed the low battery indicator. In any case, I would have known how much air she had started out with and might not have been quite so anxious during the swim back to shore from the depths.

Luck had been on our side, but it could have been a disaster. I learned my lesson. That was the last time I began a dive without a buddy check and cross-check.

The British Sub-Aqua Club (BSAC) is one training agency that does a good job of teaching and emphasizing the buddy check and cross-check to divers. They teach a mnemonic device to help divers remember the essential elements of the buddy check: B-A-R.
  • B is for Buoyancy
  • A is for Air
  • R is for Releases
Regardless of which agency trained you, think about adopting BSAC's 'B-A-R' to help you remember the items that need to be checked and cross-checked before you enter the water.


  1. Very good information.
    So glad your story turned out OK.

  2. Good points, but couldn't you have asked her (using a dive slate, by signing, etc.) how much air she had, so you wouldn't have been so anxious? I find that underwater communication is key to my dive partner's and my dives.

  3. Thanks for visiting and commenting, Becky and Laura.

    @ Laura - Oh yes, I did ask her and she indicated that she did not know how much air she had. The fact that she did not know probably made me more anxious than did the failure of the computer at 40 meters.


  4. All of your information makes absolute perfect sense. Reminds me of the checks my helicopter pilot friend has to do and how he explained a lot of times pilots will jump in without checking.

    I don't dive, can't even swim, but I find all of this so extremely interesting. Thanks for sharing.


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Bobbie & Jerry