The field process of locating a published mark from its description, confirming the stamping and checking that it has not been disturbed. A recovery note records the date, condition, any changes in the surroundings and an updated description so the next crew can find it. Marks that cannot be found after a thorough search are reported as not recovered, and a missing mark weakens the whole station's datum record.
Recovery on BM 4 is a fail, the seawall's been replaced, so mark it destroyed and level to the other four.
Photograph the mark and its surroundings at every recovery; old descriptions often point to buildings, fences and trees that are long gone.
Also heard as
- mark recovery
- bench mark recovery
Related terms
Bench mark
A permanent, stable mark of known height near a tide station that preserves the station's datums.
Brass cap
Surveyor slang for a bench mark disk, the stamped metal cap set in concrete or rock.
Leveling
Precise measurement of height differences between bench marks and the gauge or staff using a level and rods.
Station datum
An arbitrary fixed zero set below the lowest expected water at a station, used to record raw water levels.