Lead line and Writing Slate
A lead line is a device used for measuring the depth of water.
UDT swimmers recorded these measurements on a plastic slate which were compiled to create a chart prior to an amphibious assault. The method of coordinating a unit of UDT swimmers to take these measurements is called string reconnaissance. It was developed during WWII by Lieutenant Commander Draper Kaufman and his staff.
On loan from the Navy SEAL Museum
