What invention was introduced to hydrography in 1904 to improve surveying?

The introduction of wire-drag surveys in 1904 marked a significant advancement in hydrographic surveying practices. This technique involved dragging a weighted wire or chain across the seafloor to acquire depth measurements and gather information on the seafloor's features. Wire-drag surveys provided a practical method for surveying underwater terrain, particularly in shallow waters where traditional sounding methods might be less effective.

This method allowed surveyors to collect valuable data regarding the seabed, including the identification of obstructions and changes in topography. As hydrographic surveying evolved, the wire-drag technique laid the groundwork for further innovations in underwater surveying technology.

In contrast, sonar, multi-beam echo sounders, and GPS technology were developed later and represent different technological advancements that enhanced hydrographic surveying but were not part of the original improvements introduced in 1904. These technologies complement and build on the foundational methods established by earlier practices like wire-drag surveys.