As many divers are aware, we host Lock 23 dives every Wednesday evening during the summer, and because we know the routes so well, we welcome divers of all levels of experience to join us. Each week I write a review of the dive, drawing attention to issues that come up. It provides a great teaching opportunity – to remind divers of important skills, deal with unexpected site conditions, learn new tricks to make the dive more enjoyable. These have always been in the form of a newsletter, but by request, I will include many of them on this site under the heading “Teaching Moments”. Some will be reprints from last year. Many will be from this year’s reviews.

This past week marked the first time we felt conditions were safe enough to invite novice divers to join us. I am indebted to all the experienced divers who volunteer their time as guides and share their knowledge of the site so freely. We are always learning and practicing.

Divers generally found the conditions, if not ideal, quite manageable. Visibility was 10-12 feet, current variable, navigation not difficult for those who know the site. It was great to see group leaders deploy their surface marker buoys as they made their way to the beach in the final phase of the dive.

There are several dive skills that are commonly used at Lock 23; a critical one that I want to touch upon is a small component of the technique when sharing air. Why? Because this week a mistake was made… and not by a brand new diver.

In my last newsletter of 2018, I wrote in depth about the technique of sharing air. For the moment I want to discuss one tiny aspect – how to go back to your own regulator.

Here’s the scenario. Partway through the dive, it was noted that a diver would likely be unable to comfortably finish the dive with his remaining air, and the decision was made to share air in the centre portion of the dive where current is mild and the area is wide and open with few weeds. The process was uneventful. When everyone stopped as always at 15 feet for the guide to deploy his marker buoy, he waited for them to return to their own systems before proceeding. The diver who had required extra air located his own reg, inserted it in his mouth and returned his buddy’s alternate. But as he did so he drifted upwards some 3-4 feet before his buddy reached up to pull him back down. We all know it’s hard to concentrate on maintaining your position when you’ve got other stuff on your mind. The problem was not drifting up a few feet but rather that his observant buddy noticed he was not exhaling when his reg was out of his mouth. He’d customarily inhaled first in order to easily purge the reg when needed, so his lung volume was already high. If he’d surfaced from 15 feet while holding his breath, he would have increased by 50% the air volume in his lungs and possibly caused damage.

Skills come pretty naturally to us when we dive a lot. Sharing air is not one that we particularly want to utilize so it may be one in which some of the details slip in our minds. Remember those certification days when instructors always, always pointed to those tiny bubbles coming from their mouths as they exhaled whenever their regs were out, when sharing air or removing it for any other reason? It’s important. ‘Nuf said.

Sydney