Excavation
Often the water was warm (about 26°C) but at other times relatively cool (19°C). At times bait fish were prolific. In fact they were a huge nuisance as they often blanketed the excavation area, obstructing visibility and causing larger fish to dart in and out of view while they fed on the small fry!
Recording equipment such as tapes and slates were used underwater-even an ordinary pencil to write with. Each artefact was measured-in from at least four grid reference points. All this data was then transferred to an artefact record sheet and into a computer program that converted the slope distance measurements into X/Y/Z grid coordinates.
The archaeological methods had to be simple and effective. Also, all the work needed to be carried out carefully and precisely, whether it involved removal of sediment to uncover the ship's remains and the artefacts, or measuring-in, or the recovery of artefacts.
When artefacts were being excavated, they could not always be seen, either because they were very small and difficult to distinguish, or sometimes hidden in concretions. A small area could contain a wide variety of objects, ranging from tiny and fragile to large and robust, so-called, concretions.
At an average depth of 33 metres, and "digging" up to 2 metres into the seabed, diving time (using surface supplied breathing gear) was only 45 minutes per diver per day-followed by 30 minutes decompressing on a stage at 9 metres depth breathing 100% oxygen. All in all, a diver was underwater for approximately 78 minutes every day. Sometimes there were strong currents. Clear water could enable visibility of up to 50 metres; but sometimes visibility of as little as two metres made conditions on the seabed a little dark and gloomy.
A water dredge was used to gently remove sediment. Because it works like a vacuum cleaner, care had to be taken not to accidentally "clean up" artefacts. Occasionally, however, objects were inadvertently sucked up the dredge. At the end of each dive, excavators would spend time sifting through the spoil heap to see if any artefacts had been overlooked. And some were found there-surprisingly no worse for wear, despite the unceremonious journey through the water dredge's exhaust pipe. Not recommended practice however!