Abstract: The invention relates to a method of imaging a longitudinal conduit resting by its base on the seabed, comprising the following steps: acquiring a set of images of at least a part of the conduit by a mobile underwater acquisition device, each image being associated with a temporal reference corresponding to the moment of its acquisition, extracting from each image the zone included in one and the same window, said window being predefined with respect to the frame of the images, and effecting an unwrapped image of at least a part of the conduit by juxtaposing, in chronological order, the extracted zones of each image.