Wang & EF Tan Associates

Consulting & Registered Surveyors



Hydrographic Surveying is that branch of survey that is concern with the measurement of the surface below the water which can be the sea, ponds, rivers etc.


Survey vessels primarily use echo sounder and GPS (Global Positiong System). Echo sounder measures the depth of the water while GPS measure the position of the depth. In shallow water, lead sounding may be used instead of echo sounder. Here a heavy lead is lowered into the floor of the pond or river and the depth is measured with a tape attached to the lead.

Hydrographic Survey are carried out usually in construction of wharfs, bridges etc where structures constructed over water.

Please Contact us if you require further information