Abstract: The invention relates to a method of externally locating anomalies inside a hollow structure which is positioned on and/or below the ground (PL), wherein said anomalies have been previously detected by a device (RTE) moving inside the hollow structure and positioned by counting a series of reference marks from an origin, said reference marks being located at regular intervals and being accessible from the inside and outside of the hollow structure (PL). The inventive method comprises the following steps consisting in: a. defining by means of courting a reference mark, starting from said origin, which is accessible from outside of the hollow structure; b. positioning a transponder module (T) on said reference mark; c. identifying the transponder module (T) by an I.D. code; and d. determining the number of reference marks separating the anomalies and the identified transponder module (T).

Abstract: A method for externally locating anomalies located inside an immersed hollow structure (PL), wherein said anomalies are previously detected by a device (RTE) moving inside said immersed hollow structure, and are positioned by counting a series of reference marks from an origin, said reference marks being located at regular intervals and being accessible from the inside and outside of said immersed hollow structure. The inventive method consists in defining by means of counting a reference mark, starting from said origin, which is accessible from the outside of the immersed hollow structure; positioning a transponder module (T) on said reference mark; identifying the transponder module (T) by an I.D. code; determining the number of reference marks separating the anomalies and the identified transponder module (T).