Classicly

Travis remembered the polyps in the Venusian water-caves where he'd almost lost an arm before he got past them to bring the museum the only specimen of the primal undine race of Venus ever seen above the sea-mists. He had found a petrified boat on Sirius' third planet, to prove that at one time there had been seas on that baked potato of a planet. But for the last six months he had moped around Mars Port, studying alluvial deposits, wishing for something to take him and his equipment out into the star-paths again.