For the last two years I have been using the Drop Tech Case for iPad to protect my iPad in the field. This is a very rugged case although, as I mentioned in my post, not waterproof. I had got over this problem by using an Aquapac waterproof case but, although the combination worked, it was not an ideal solution.
I was therefore delighted to discover the Griffin Survivor Military-Duty Case which, as its name suggests, is manufactured to comply with the MIL-STD 810G testing protocols.
The case has been tested for a drop of 6 feet, and is proof against wind-driven rain, sand and dust. In short, it should protect against the type of conditions that field archaeologists will encounter.