Saturday, August 20, 2011

Dive 186 - Union Lake After the Storm

Dive 186 had its start was delayed today due to a very heavy thunderstorm that rolled through the area.

Thankfully, the thunder, lightning and rain finally ceased and Keith and I could safely get in the lake.

The visibility varied from a high of CSS to a low of SFA
(Sweet F_ All if you haven't figured that one out), basically a foot or less.

We were able to find the line and get out to the sunken boats and do some low viz practice.

We then did a no-mask line drill.

For a no mask line drill, as it is named, you take your mask off and follow the line to and from a destination by holding it in a O formed by your thumb and finger(s). Once you've gone back and forth on the line and get back to the start you can put your mask back on. The other diver supervises while you do it and then you switch off.

The drill is useful to practice situations when the visibility inside a cave or wreck becomes silted up and you have to get back to the outside by following your guideline back to the entry point.

Happily the water was pretty warm - 72 at the surface dropping to 64 at the bottom. There was quite an interesting thermocline - the level where the temperature changes, was actually inside one of the boats creating a very neat visual effect of the bottom of the boat appearing under a shimmering layer while the top of the boat was clear.

With warm water, removing the mask was relatively pleasant and we did a pretty long distance drill - going from the bars on one boat to another from stem to stern and then to the bow of the sunken pontoon and then back. As the line was tied off in various spots and into Ts with other lines, you had to pay attention to where the line you wanted ran so you could get where you needed to go.

The drill certainly shows the value of a guideline to get out of a silted out situation. With eyes shut, even as I went straight along the line I felt like I was going in circles. In a silt-out your instincts as to where the exit is will likely be wrong. This is why you don't go into caves or wrecks without a guideline (not to mention training, lights and a sufficient breathing gas supply).

So it was a good 50 minute dive with 800 psi used, and after the standard safety stops, the dive came to an end.

My Orange gloves, with the right hand now fixed, were leak proof and quite dextrous, so a comfy and dry dive was had.

A useful training dive indeed.

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