Complex sentence: RESON of Santa Barbara, CA and Slangerup Denmark, developed the "SeaBat" range of portable multibeam echosounders were the systems widely accepted for shallow water hydrographic surveying to make harbor charts.
Split into simpler sentences: RESON of Santa Barbara, CA and Slangerup Denmark, developed the "SeaBat" range of portable multibeam echosounders. The systems are widely accepted for shallow water hydrographic surveying to make harbor charts.