The surface coating is spalling from the outcrop and produces rubble in the form of slabs that are concentrated at the base of the scar. Overall, the basal part of the scar is smooth and clean looking with little biological growth. Two benthic ctenophores attached to a piece of wood, left, reminded us of our own ctenophore specialist, George Matsumoto. A less pronounced upper part of the scar is also composed of mudstones and forms a vertical cliff. This cliff is capped with slabs of extensive bioturbated well lithified mudstones.
Sea fans grow on the vertical face of the mudstone wall, at right.
The canyons that were investigated during this series of dives appear to be active sand transport conduits. Whether the sand is locally derived or transported from the streams that drain from the Kohala area is unclear. However, the rounded sides of the canyon walls suggest that erosional undercutting associated with the moving sand continues to destabilize the canyon walls. No evidence of fresh water sapping or other fluid seeping processes were found.