4.20B Locating and Marking in Navigable Waterways

Facility Owner Locator

B: Temporary Markers for Underwater Facilities13 

Practice Statement:

Temporary markers are placed within the areas of proposed excavations as close as practical over facilities that are submerged in bodies of water where facilities are at risk of being damaged without impeding or creating additional hazards.

Practice Description:

The technology used to locate and mark the submerged facility is dependent upon the size of the facility, depth of water, material composition of the floor, and the depth the facility is positioned in or on the floor of the body of water. Temporary markers such as buoys, poles, or PVC markers are used by underwater facility owners to indicate the presence of an underwater facility in the area. At times these markers may be supplemented with mapping, GPS coordinates, and/or fixed high-bank marks. There are many excavating activities, such as dredging, bridge construction, setting of anchors, and directional boring, that can damage underwater facilities. The proper placement of visible temporary markers raises the awareness of these facilities and reduces likelihood of damage. Communication between stakeholders is initiated through the one call center to reduce potential conflicts. It is critical for stakeholders to maintain communication throughout the excavation to ensure the safe and successful completion of the project. Placement and removal of temporary markers for underwater facilities follow local, state, and federal laws and regulations.


  • By alerting excavators to the presence of underwater facilities, temporary markers provide additional protection to excavators, facilities, and the public.


  • Sunshine State One Call of Florida, State of California Code, State of Delaware Code, State of Alabama Code, State of Mississippi Code


One Call Center One Call Center

Facility Owner Facility Owner

Excavator Excavator

Locator Locator

Project Owner Project Owner

Designer Designer