Quote: (Originally Posted by
Joe Hesketh)

NAS do, but this is typically a large A4 sheet pasted onto a chopping board

If you used one with a handle then couldn't you rig a leash/boltsnap and job's a good 'un?
Quote: (Originally Posted by
Joe Hesketh)

Also, their detailed survey techniques involve using tape to take multiple measurements of individual points on each object. Each point is given a 3D position by measuring it's distance from at least two known fixed points on the wreck, which is impractical for our project.
Fred's sheets are fine, after all what we're doing is much more akin to cave survey than what the NAS generally do.
Fair enough, but can I ask why the NAS approach is impractical in this case? I know very little about this stuff and find it interesting, so I'm curious to hear why you're having to adapt the techniques.