I rarely dive greater than about 35m because there is almost always more to see & photograph in shallower waters than there is down deep.
So it’s usually either a wreck, or some other very specific thing to see, that gets me into deeper waters and means I have very little tolerance of nitrogen narcosis – or as Jacques Cousteau so eloquently put it, “the raptures of the deep”.
As every trained diver knows, the deeper you go the higher is the partial pressure of nitrogen you are breathing.
Once you have past the 30m threshold, the so-called “Martini effect” kicks in and a significant increase in over-confidence occurs, coupled with a marked decrease in the ability to rationalize things and do basic calculations.
This was all brought home vividly to me on my recent trip to Tufi when I embarked upon the task of photographing the wreckage of what is left of the two PT Boats laying on the bottom of Tufi fiord at 50m.
I had figured it would all be a fairly straightforward exercise as I could set my camera up for wide-angle photography the night before. Then use if on the offshore reefs in the morning and once back at Tufi Wharf, go for a mid-afternoon dive on the PT Boats without having to change anything around – too easy…
But nitrogen narcosis and underwater photography are words that should not really be used in the same sentence, never mind practiced….
It took me five attempts to get the images – simple camera & strobe adjustments that are made without even thinking at 20m seem to become major philosophical judgment calls at 50m and it was with an increasing sense of shame that I had to report to my Japanese underwater “supermodel” & Tufi divemaster Yuko Kuramoto that each day’s attempts had failed.
That was until I realized that Yuko was suffering from the “narcs” possibly as much as I was when, despite all my pleas not to do so, she kicked up the bottom and reduced the visibility to about 2m – or forgot to turn on the torch…. There is a great saying in PNG Pidgin that we came to use as it kind of summarized the impact of narcosis at 50m – “head, him no good..”
But I am glad to say that by attempt number 5 we were both comfortable at 50m and the seven minutes we had allowed ourselves at that depth went completely to plan and I was able to use the 23 minute decompression stop near the Tufi Wharf to review some decent images!
Check out the PT Boat page for a full description of the wrecks and their history.