June 15, 2010

Today was an action-packed day that included a practice dive and several fascinating lectures on various topics of maritime archaeology .

This morning after breakfast we got our first chance to get into the water so we could practice 2D measuring techniques such as the offset method and trilateration.  This practical session allowed students to build on these same measuring techniques that we learned yesterday in the comfort of the parking lot where communication and buoyancy were not a problem.  After completing our measurements we were then asked to draw artefacts using a planning frame.  Overall, this dive session gave me a deeper appreciation for the difficulty of operating under water while needing to be efficient and accurate.  I was happy with our results but I would definitely benefit from more practice.

After a quick turnaround that included a shower and a cup of tea we had the opportunity to learn a great deal about the capabilities and benefits that remote sensing can offer the discipline of maritime archaeology courtesy of Mark Lawrence.  Some of the technologies that Mark covered included side scan sonar, magnetometer, sub-bottom profiler, and the different ways of position fixing that make all the data more useful.

We again recharged our batteries with tea, coffee, and biscuits and then got settled in to hear from Sara Hasan about the vitally important issue of safety and logistics while planning archaeological projects. This phase of planning can make or break a project if sufficient time is not devoted to ensuring the safety of the team and the types of equipment needed to achieve the project goals.

Mary Harvey then gave us a thorough talk about conducting 3D surveys underwater.  Determining the number, placement, and depths of control points is best handled after an assessment dive over the site.  We practiced this technique on shore to make sure we understood the concept and could put it into practice underwater.

Next, Mary gave us an overview of how to deal with artefacts on a site and the questions that need to be answered before an artifact is raised up from the seafloor.  She described the methods to be used to provide first-aid to artefacts before they reach a conservator.

We covered a lot of ground today and it was all interesting and informative.  I would highly recommend attending an NAS fieldschool.  The instruction is fun and excellently delivered.

Dan Hudson