 When commissioned, "Explorer" was considered to have the finest and most extensive hydrographic surveying equipment in the history of the Coast and Geodetic Survey′s fleet, all entirely electrically powered.The equipment included a fathometer, a Dorsey sonic depth finder, a Hughes automatic depth recorder system, a special taut-wire measuring gear with 120 nautical miles (138 statute miles; 222 km) of fine wire and several tons of iron balls, and hydrophones.Electrolysis eliminators mounted to her hull ensured that she would be grounded so as to avoid interference with her electrical surveying equipment.