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Solo Dive at Big Bay Point July 25, 2009

Posted by Chris Sullivan in Dive Log.
Tags: , , , , , , ,

I’ve done precious few night dives in my time, 3 to be exact, or just over 1% of my total dives. At this time of year in Canada sunset is around 9pm, at which time I’m usually thinking about retiring for the night, being a fairly early riser. Last Wednesday night was no exception. The dive club was meeting for an afternoon dive then a night dive, and rushing back from my job in downtown Toronto I managed to arrive just after 7pm, just in time to be too early for the night dive and too late for dive #1.

The conditions were excellent that evening. There was barely a ripple in the water and the air was warm. Half a dozen fishermen were on the dock, so I was careful not to be too near their lines when entering the water or swimming out to the float, which had already been set up by the other divers.

With all the other divers either already in the water or just on their way out, I had no buddy. I elected to dive solo, reasoning that for shallow dives  I was no worse off than when teaching uncertified students. So in the water at quarter to eight, I headed initially to my maximum depth of 53′, returning quickly to the two inboard/outboards lying together at 40′, where I saw a couple of large Carp. In my haste to pack my car the night before, I’d forgotten one of my gloves which had dropped behind my lawn tractor out of sight. Fortunately the water wasn’t too cold – 62F (17C) at the deepest point but much warmer for most of the dive so I wasn’t bothered by its absence.

After examining the Carp for a while, I followed the line from the postbox out to the speedboat, which lies at a depth of 30′ well east of the main line. There were several bass hanging around it, none caring that much about my presence. At this point I thought it might be nice to practice underwater searches, so I tied a line to a cleat on the topside bow of the boat, and commenced a pendulum search in a semi-circle running from directly east, to north, then west of the tie-off point.

With each swing of the pendulum, I let out more line from my reel – about 4 frog-kicks worth. This sculling kick is taught in the wreck course and soon becomes habit, as it is both a comfortable means of propulsion and avoids stirring the bottom, even when the diver is very close to it. While our wreck students claimed having difficulty mastering it, we pressed them at it to help them learn to swim through wrecks without wrecking the visibility.

There is not much to be found in that area of the lake. The only thing to be seen other than a few weeds and Zebra Mussels was a telephone pole mostly submerged directly north of the speedboat lying NNE to SSW I held my compass against the reel so that when it read South I would know to turn around. That was quite effective and I noticed that the Lake was slightly shallower (about 27′) at the Easterly extremity of the search pattern. Eventually, I decided that my air supply was at the point where I should return to the float, so I tied a knot in the line to mark my greatest distance from the speedboat. I measured it today at just over 80 feet.

Now the circumference of a circle can be found using the formula 2πr, so a semi-circle would just be πr, or for me about 251 feet. I counted 107 frog kicks on my maximum traverse, or about 2.35′ per kick. I will admit right now that this wasn’t very much, but I was kicking gently so as not to stir up the silt.

The area of a circle is the old familiar formula πr², so my semicircle is just half that, which means that I searched an area a smidgen over 10,000 square feet. This is exactly the requirement for the larger area search for the Search and Recovery Diver Specialty dive #1, so it’s a good one to bear in mind.

Once I’d recovered the line onto my reel and untied it from the cleat, I headed back to the post box and the security of the ascent line to the float and flag. I hung around there looking around for a while and was just hanging there practicing neutral buoyancy in a horizontal position. I noticed that with 10lbs of weight in my weight pockets and the single tank adapter on my OMS backplate and wings, that I tended toward the vertical position. In the same rig and a dry suit I tend toward horizontal when the doubles are mounted, but with no weight. I’ll have to find a way to move my weight forward. In the wet suit, the BC is slightly loose and I can pull it up a bit which makes the trim better but that’s not the best solution by a long shot.

My horizontal meditiations were suddenly disturbed when I caught a massive silt cloud looming in the corner of my eye. 3 divers had arrived, and one was vertical and kicking furiously, blowing up silt like an approaching thunderstorm kicks up dust in its wake. I waved, then deciding it was as good a time an any to ascend, made a slow free ascent next to the line with a 3 minute safety stop. With almost no current it was easy to just hang there and weight out the countdown on my computer.

As I left the water the sun was just setting, 10 minutes before official sunset. Another opportunity for a night dive gone. The water was still calm and the air still warm, so a had a pleasant slow swim back to the dock, so unlike the conditions I’ve often encountered where we’d be struggling in our gear against the wind, waves and current. The fisherman will still there after a dive of exactly 60 minutes, and I headed back to the car to unload everything in a head into the trunk to make a quick exit, made all the more urgent by an email from my wife stating she was on an earlier train.

I broke several provisions of the highway traffic act to get the train station in reasonable time, only leaving her waiting for about three minutes, and we both headed home for the night.



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