1.Previous
3.Next

modern times, echo sounding is used for measuring the seabed in the open sea. When measuring the safe depth of water over an entire obstruction, such as a shipwreck, the minimum depth is checked by sweeping the area with a length of horizontal wire. All depths on charts is measured with respect to a datum/reference level. This ensures that difficult to find projections, such as masts, do not present

1.Previous
3.Next