Maxperson
Morkus from Orkus
Not necessarily. I found this in the DMG. It talks about distance alone, not any factors that would make it harder. That implies that if the DM thinks that there should be a check involved, there is, and the DMG thinks distance is a reason to add such an ability check.It’s a save, not a check, the difference being that the action (swimming) succeeds, no check. Having to make a save is a consequence of the successful action, and failing the save doesn’t prevent continued successful action unless too many levels of exhaustion accrue.
"Under certain circumstances, you can decide a character's proficiency in a skill can be applied to a different ability check. For example, you might decide that a character forced to swim from an island to the mainland must succeed on a Constitution check (as opposed to a Strength check) because of the distance involved. The character is proficient in the Athletics skill, which covers swimming,..."