A horizontal outfall near the seabed is occasionally adopted in engineering practice for the submerged discharge of dense jets. Upon exiting the nozzle, the horizontal dense jet would curve toward and impinge on the seabed due to the negative buoyancy. The boundary interactions between the discharge and the seabed would intensify if the offset between the outfall and the seabed, or the bed proximity, reduces. Quantitative assessment of the boundary impingement and attachment of the offset dense jet is studied experimentally using Particle Image Velocimetry (PIV) and Planar Laser Induced Fluorescence (PLIF). Boundary-influenced and free horizontal offset dense jets were investigated by varying the discharge densimetric Froude number, Fr, as well as the bed proximity parameter z0/LM. Various relationships of the impingement characteristics were established through the analysis of the experimental results.