A method of and apparatus for assessing a condition of a fluid conduit is described. The method comprises providing a measurement apparatus comprising at least one wideband acoustic transducer internally or externally of a fluid conduit, and transmitting a wideband acoustic signal from the measurement apparatus to excite at least a portion of the fluid conduit. A wideband acoustic signal is received in the measurement apparatus to obtain a wideband acoustic data set; the wideband acoustic data set is analysed to assess the condition of the fluid conduit. The wideband acoustic signal comprises frequencies in the range of approximately 10 kHz to approximately 150 kHz. Applications include detecting or assessing a layer or deposit on an interior of the fluid conduit and assessing a physical condition of the fluid conduit. Water ingress into an annulus of a multiple layer conduit (such as a flexible riser) may be detected.