In 1847, Sarah Mather, an American inventor, patented the "submarine telescope and lamp," a device for inspecting ship hulls submerged in water. Combining a waterproof lantern and a telescopic tube, it allowed inspections without costly dry docking. Initially met with skepticism, it later influenced nautical maintenance practices, enabling safer, efficient ship management. This innovation exemplifies the significant, yet often overlooked, contributions of women in 19th-century technological advancements.