A computer-implemented method for detecting at least one natural contour of a geologic object in 3D seismic data, the method comprising the steps of: (a) receiving at least one first predetermined data set from said 3D seismic data comprising a plurality of phase events; (b) selecting at least one first seed phase event having a first phase characteristic from said plurality of phase events; (c) determining a characterising score between said selected at least one first seed phase event and every one of reachable candidate phase events having said first phase characteristic of said at least one first predetermined data set; (d) assigning said characterising score to every one of said reachable candidate phase events; and (e) adjusting said characterising score of at least one of said reachable candidate phase events in accordance with at least one first boundary condition comprising at least one geologic constraint and/or at least one stratigraphic constraint and/or at least one algorithmic optimisation constraint in accordance with at least one variable of said at least one candidate phase event; characterised by : (f) determining an optimal path and at least one alternate path of a natural contour between said at least one first seed phase event and at least a second phase event based on an accumulated score of said characterising score of every one of said reachable candidate phase events utilising an optimisation algorithm, wherein said accumulated score comprises a sum of the characteristic scores of the candidate phase events traversed by said optimal or alternate path; and (g) generating a visual representation of said optimal and at least one alternate path of a natural contour within said at least one first predetermined data set. (a) receiving at least one first predetermined data set from said 3D seismic data comprising a plurality of phase events; (b) selecting at least one first seed phase event having a first phase characteristic from said plurality of phase events; (c) determining a characterising score between said selected at least one first seed phase event and every one of reachable candidate phase events having said first phase characteristic of said at least one first predetermined data set; (d) assigning said characterising score to every one of said reachable candidate phase events; and (e) adjusting said characterising score of at least one of said reachable candidate phase events in accordance with at least one first boundary condition comprising at least one geologic constraint and/or at least one stratigraphic constraint and/or at least one algorithmic optimisation constraint in accordance with at least one variable of said at least one candidate phase event; (f) determining an optimal path and at least one alternate path of a natural contour between said at least one first seed phase event and at least a second phase event based on an accumulated score of said characterising score of every one of said reachable candidate phase events utilising an optimisation algorithm, wherein said accumulated score comprises a sum of the characteristic scores of the candidate phase events traversed by said optimal or alternate path; and (g) generating a visual representation of said optimal and at least one alternate path of a natural contour within said at least one first predetermined data set. <EOS>