I'm trying to identify a novel or novella, probably from the 70's or 80's, a typical sci-fi bildungsroman, with teens on a starship training for some survival test of being dropped on a planet. It's NOT Tunnel in the Sky or Rite of Passage, but in a similar vein. In this particular story, part of the preparation for the final survival test involves a section of the spaceship set up as a wilderness testing ground, with a "race" (the order in which people complete the task) determining some benefit in the final on-planet test. The protagonist does well in this "pre-test" by virtue of being the only one (or one of the only team of 2, perhaps) to swim across some body of water rather than going around it.
This pre-test is not the bulk of the story, it's just the part I remember.
For a long time I was convinced that this was a scene from Rite of Passage, but when I reread that, it wasn't there!