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n March 1992 it was decided that the MAAV would undertake a project on the Carmen and that a site plan should be produced. An experienced team of MAAV members visited the site on March 27, 1992, in order to establish a base line for the triangulation procedure. To those of you who don't know what triangulation is, it is a task so simple that it almost does the job itself. Imagine a triangle, if you know the length of the base you can measure off either end of this one point where you have created a triangle, plot these measurements onto a chart and providing you have enough measurements, a site plan can be produced, it's as easy as that.
A tape measure was let out on the sand at the base of the reef where the wreck is located. Wooden pegs about 300mm long were driven into the sand next to the tape with about 50mm left showing. Roofing nails were hammered into the tops of these.
Now, this sounds like an easy task to perform, it is on land, but imagine that you are nearly blind and that you only have half your normal strength while someone is bending you backwards and forwards at the waist and throwing cups of water at your eyes. I can't believe I do this for fun. The average person can then get a better picture of what it is like to try and do something like this underwater. The pegs were driven in over a distance of 30 metres, three metres apart. On the first day, you couldn't see from one peg to the next - great viz! Now you might think that it would be super to have all of these pegs on the bottom in a nice straight line, three metres apart, but what is the good of it unless they are numbered so that you know where you are when you are measuring from the base line. Well, they wouldn't be much use at all so they had to be tagged and numbered. But what could be used? It had to be low tech, cheap and easy to produce, and what could they be made from but old margarine containers. Thank goodness we hold onto our used ones - they were cut into small tags and numbered from one to ten with a felt tip pen.
Roofing nails were driven through the holes punched into the tags and into the tops of the pegs. By the time this had been completed, a strong south wind had blown up stirring the bottom into something that resembled pea soup. The day's activities had to be suspended until another time. In May 1992, the rest of the team returned to finish the triangulation. What did we need to finish off the job? A few tape measures and a few underwater slates, as well as a thermos of coffee!
The return expedition was a complete opposite, weather wise, with blue skies and a beautiful ten metres of viz. We could actually see a few pegs in the distance along the base line. The team quickly got to work and measured all the major pieces of triangulated base line wreckage, most of which was iron knees. The measurements were written onto the waterproof slates.
Now hang on a minute, this task sounds so simple, what's the point of writing about it? Well use your imagination again, put half a dozen pairs of footy socks over your hands, then shove them into some ice cold water for half an hour or so, try to write something, then you can gain a better idea of what is involved. In the end it is almost a two handed operation to write, and it takes all your strength just to hold onto the pencil.
When all the measurements were complete a site plane was produced by using a T-square, drawing board, a scale rule and a compass. It's usually hard to get an overall vision of a site underwater, but once it is drawn up on paper, you can see how it all fits together.
