Let N be a set of n points in convex position in R-3. The farthest point Voronoi diagram of N partitions R-3 into n convex cells. We consider the intersection G(N) of the diagram with the boundary of the convex hull of N. We give an algorithm that computes an implicit representation of G(N) in expected O(n log(2) n) time. More precisely, we compute the combinatorial structure of G(N), the coordinates of its vertices, and the equation of the plane defining each edge of G(N). The algorithm allows us to solve the all-pairs farthest neighbor problem for N in expected time O(n log(2) n), and to perform farthest-neighbor queries on N in O(log(2) n) time with high probability. (C) 2002 Elsevier Science B.V. All rights reserved.