The area where the oarlock holders were located for a 13-foot early classic hull was part of the mold and included the recessed rectangular area for the flange of oarlock socket, and the deep recess for the socket was also gel coated in the first layer of the liner layup build, because of that design there is really no way water can get into the foam interior of the Unibond hull.
However the screw fasteners must be sealed with a proper sealant.
See Figure 1 below for close-up views.