Yes, I was assuming that, because that's all you described: sailing across water.
The point I'm making is that if it was a deliberate choice to choose sailing over another option then, yes, the players should be weighing the risks/rewards of both (many?) options.
But if it's just something they need to do in order to continue the adventure, then they aren't really making a choice, even if they "elect" to do it. Any more than I'm choosing which card to play next in the card game War.
Forcing a dice roll with potential consequences in that case is not really "playing a game", it's just imposing simulationism.
One could argue that "playing the game" involves some amount of being subjected to simulationism, but why? Why not excise those parts? We all have a finite amount of game time; I'd rather spend those precious minutes having players make interesting decisions.
I thought I had explained that multiple times, but I'll try again: by "given" I mean are there other alternatives, whether or not the GM offers them. And the litmus test is whether the decision is hard. If there are other choices, but not really any that can compete with sailing (in terms of risk:reward), then I would either eliminate the risk, or adjust the options to make them more appealing (maybe by making the sailing even riskier) so that it's actually a tough decision.
My inclination there is to narrate past the uninteresting part. "Yes, you can take the sailboat across the lake. None of you know how to sail so there's a bit of comedy on the way, but you get there, noticeably more damp than before you embarked."
Again, play time is precious. I want to save it for the good stuff.