Scott Benson's Final Advanced Open water dive (Underwater Navigation)

Evan Davis's Advanced Underwater Navigation core dive

Russell Bowen and Cobus Vandenberg's 3rd Open Water training dive

Training: This was a complicated dive but fun to execute. I had two groups of two divers each. My advanced divers were doing 4 skills (1) tracking kicks and time over 30 meters (2) as a buddy pair, navigating to a known point and return using underwater reference points (3) each navigate out and back 30 meters on compass, and (4) navigating each a square pattern. For them, I had on hand a 30 meter line and a plastic bag, inside of which were two more plastic bags, each containing small stones.

We went down a buoy line and attached my line to it. I then reeled out the line and the divers followed. At the end of 30 meters, I had each advanced diver record on a slate the time and fin kicks for 30 meters. We left the plastic bags there: the two small bags next to a rock with the plastic bag that had been holding them. We had in the briefing before the dive established that this would be point A.

I then took my o/w students back to the anchor line while taking up the line. I had the advanced divers wait till we were out of site with instructions to meet us at the anchor line by finding their way using natural reference points. In fact, the bottom at Delta Buoy is pretty nondescript and flat with little in the way of natural reference, so Evan soon emerged from the gloom holding his compass ahead with Scott in well in tow (supposed to be counting kicks, though he didn't appear to be in a position to have stopped Evan had Evan missed his mark).

It was then Scott's turn to lead us back to point A using natural reference, but he probably took out on a northerly heading and in any even we arrived at the plastic bags minutes later.

As luck would have it there was a sand patch there, so Russell and Cobus and I settled into a skills portion while Evan and Scott went on 30 meter forays east and west. Evan's mission to the west was to leave one of the plastic bags with a stone at point B, 30 meters away at 270 degrees. Scott's was merely to head 30 meters ninety degrees and return to point A. While waiting, Russell and Cobus and I disconnected our low pressure inflators and deflated BCD's. They then did full mask flooding while heavy in the water, and were then in a position to re-inflated BCDs orally while in the course of resuming neutral buoyancy. We had just finished the option buddy breathing when the advanced divers returned from their scouting missions. Cobus is from South Africa where I'd noticed they don't always have octopuses, so I thought buddy breathing training would be a good idea.

Next, the advanced divers led us on a square. I followed with the o/w divers to point B, where Evan had left the first bag. Evan (leading) turned south and left another bag at point C. A westerly heading put us back at the anchor line, and here I took my o/w divers up in a buddy breathing ascent.

The advanced divers had been instructed to return with the bags. To retrieve the bags, Evan would have to return them to point A, and Scott would then retrace the square and pick up the litter en route. The area was so featureless that there was little chance of feature recognition polluting the exercise. In this respect, it was an ideal training ground for advanced underwater navigation dives.

Topside, I had my o/w guys take a bearing on Delta Buoy and one swim there head down while the other followed in snorkel / reg exchanges. At the buoy (I told them to listen for the bell when Cobus's head would strike the buoy) we reversed and Russell led us back to the boat on compass. At the boat we relieved cramps before exiting the water to switch tanks for the second dive. At about that point, Scott and Evan reappeard with all the bags.

Surface interval duration actual: 25 min

 Russell Bowen and Cobus Vandenberg's 4th and final Open Water training dive

Training: We descended down the buoy line and at its base removed and replaced masks and hovered near the buoy line. Cobus and Russell then each performed an out compass heading at a given number of fin kicks and each returned perfectly to the buoy. There wasn't much to see in the water so to model the procedure for them, I led them in a square pattern south, east, north, and west back to the buoy. We ascended, and they're divers.