3D documentation of shipwrecks embedded in seafloor
sediments, and not visible above it, is potentially an
important aspect of maritime archaeological survey and
management. Known shipwrecks embedded in the sea floor have
been registered in 3D as part of 3D chirp-system research, which
focussed on these specific features. But this method is expensive,
time-consuming and complicated to handle. This presentation
will discuss a development in the direction of a faster, cheaper
and less complicated method, consisting of Chirp acquisition in a
rather dense 2D grid that need not be regular. The presentation
is based on the results of ongoing survey work in the Akko
Harbour area, off the Carmel Coast, Israel. The results show that
the hull of the detected shipwreck, and its shape, can be nicely
identified and that sedimentary units bounding the hull can be
outlined and interpreted. Based on an interpretation of the
outline of the curved hull, the depth was measured, and a 3D
image of the shipwreck produced. Samples of the subsea floor
have been obtained from the area, and the one located with the
extent of the mapped shipwreck contained wood fragments. The
presentation shows that 2D surveying is an alternative to 3D
surveying, as it is cheaper, faster, less complicated to operate, less
sensitive to weather conditions and can produce good results.