Star Born by Andre Norton

Familiar only with the wave-riding outriggers, Dalgard took his seat in the alien craft with misgivings. And oddly enough it also bothered him to occupy a post which earlier had served not a nonhuman such as Sssuri, whom he admired, but a humanoid whom he had been taught from childhood to avoid -- if not fear. The skiff was rounded at bow and stern with very shallow sides and displayed a tendency to whirl about in the current, until Sssuri, with his instinctive knowledge of watercraft, used one of the queerly shaped paddles tucked away in the bottom to both steer and propel them. They did not strike directly across the river but allowed the current to carry them in a diagonal path so that they came out on the opposite bank some distance to the west.

Sssuri brought them ashore with masterly skill where a strip of sod angled down to the edge of the water, marking, Dalgard decided, what had once been a garden. The buildings on this side of the river were not set so closely together. Each, standing some two or three stories high, was encircled by green, as if this had been a section of private dwellings.