This method, executed in a group of nodes of the ad hoc network (1) including a source (10), first and second relays (11, 12) and an addressee (13), the relays being neighbors of the source, the addressee being a neighbor of the relays, the source having useful data to be retransmitted towards a final addressee (15) through a routing path passing through the first relay (11), and then the addressee (13), consist of: computing a first characteristic quantity of an elementary path between the source (10) and the addressee (13), via the first relay (11) and a second characteristic quantity of an elementary path between the source (10) and the addressee (13), via the second relay (11); verifying the observance of a criterion for the first characteristic quantity; and, in case of negative verification, using the second relay (12) for relaying the useful data from the source (10), towards the addressee (13).