What is the DC to swim through Wall of Water?

The answer to this question significantly impacts how good of a spell it is.
Considering it's a third level spell, I don't think it should be equal to the spell DC.
Nothing in the spell description describes the quality or stillness of the water, so I'm unsure which of the non-level based DCs would apply.

Looking at the art in the blog post looks kinda "swiftly flowing river" to me, but I'm really grasping at straws when I'm trying to discern rules from art.

I would assume it to be the DC of the spell.

Considering it's a third level spell, I don't think it should be equal to the spell DC.

Why wouldn't it be the spell DC?

Are there any cases in which the DC of something involved in a spell that isn't a flat check is explicitly not the spell DC?

Ectar wrote:

Considering it's a third level spell, I don't think it should be equal to the spell DC.

Why wouldn't it be the spell DC?

Are there any cases in which the DC of something involved in a spell that isn't a flat check is explicitly not the spell DC?

Couple of reasons why I don't personally think it should be vs spell DC:

2.) Every spell I can think of that has a secondary check/save uses something that automatically progresses.
A lot of things use Escape checks, which at LEAST progresses with unarmed attack proficiency, which all characters have, but also Acrobatics and Athletics. Maze uses perception checks or survival. Every other spell I can think of uses either a save or their choice of a save or skill check.
I can't think of any other spell that would require exactly one kind of skill check to overcome.
And because ONLY athletics can bypass the wall of water, a ton of non-athletically inclined characters would be SOL. Even having a swim speed doesn't guarantee success if the water is turbulent, which isn't specified either way by the spell.

3.) Because nothing in the spell says that that's what the DC is.
Using Entangle and Maze as examples:
"Creatures can attempt to Escape at entangle's DC to remove these effects."
"Once each turn, the target can spend 1 action to attempt a Survival check or Perception check against your spell DC to escape the maze."

In other spells I've looked at, if the spell gives the victim a kind of skill check to escape/reduce the effects, the wording of the spell specifies that the check DC is the same as the spell DC.
Here it doesn't.

1.) Swim DCs are typically simple DCs, not level-based ones.

That's not actually relevant because it is explained by the typical case of a swim DC being from a thing without a level.

2.) Every spell I can think of that has a secondary check/save uses something that automatically progresses.

Those also inflict an effect upon a character. Wall of water, being a wall, can't be thrown onto a character so the character must be choosing to attempt to swim through it before the DC comes up, making the comparison not really 1:1 - it's not unfair of the game to expect that someone choosing to attempt to swim has put a resource into being more capable of doing it.

3.) Because nothing in the spell says that that's what the DC is.

On this point, you're confusing helpful reminders for mandatory mentions. The general rules for setting DCs tell us a check/save against a spell uses the spell's DC as a default, it isn't actually required that every spell specify that detail.

2.) Every spell I can think of that has a secondary check/save uses something that automatically progresses.

Those also inflict an effect upon a character. Wall of water, being a wall, can't be thrown onto a character so the character must be choosing to attempt to swim through it before the DC comes up, making the comparison not really 1:1 - it's not unfair of the game to expect that someone choosing to attempt to swim has put a resource into being more capable of doing it.

Nothing in Wall of Water indicates that it cannot be placed in the same space as a creature, nor do the general rules on Walls.

3.) Because nothing in the spell says that that's what the DC is.

On this point, you're confusing helpful reminders for mandatory mentions. The general rules for setting DCs tell us a check/save against a spell uses the spell's DC as a default, it isn't actually required that every spell specify that detail.

The general rules for setting spell DCs tell us for a saving throw against a spell, you use the caster's spell DC. Nothing is mentioned as a general rule for setting skill DCs.

2.) Every spell I can think of that has a secondary check/save uses something that automatically progresses.

Both Spell DC and Athletics check to swim automatically progress with level. At least as much as an Acrobatics check to escape does that you reference with Entangle.

So what are you talking about with point #2 here?

Ectar wrote:

2.) Every spell I can think of that has a secondary check/save uses something that automatically progresses.

Both Spell DC and Athletics check to swim automatically progress with level. At least as much as an Acrobatics check to escape does that you reference with Entangle.

So what are you talking about with point #2 here?

Every character IS trained or better in all saves as well as perception.

Every other spell I can think of has SOME option for EVERY character to use a modifier that receives your level-based scaling without requiring any additional investment, because they're things that always receive level-based scaling at at least trained level. Being saving throws or perception.

Given that, from a dice-roll perspective, wall of water can ONLY be defeated via athletics, which not all characters have, I'm positing that it should have a basic DC, not a level-based one.

Wall of water is only 5 ft thick. You only have to make an athletics check to traverse it, not to exit the wall.

Yeah, creatures with no ability to swim are going to have trouble going through the Wall of Water. Even so, it doesn't seem to be that overpowered. For creatures that do have training in swim, the wall is not much more than a minor hindrance. Much like Wall of Wind. Wall of Fire doesn't actually prevent movement at all - just disincentivizes it. Wall of Stone, Wall of Ice, and Wall of Force are all much better at preventing creatures from crossing. None of them allow any skill checks at all for moving through them.

While true, at least ice and stone can be broken somewhat reliably.
Force is much harder to deal with.

Also, though a DC isn't given, I can't think of a reason why you couldn't climb a wall of stone.

But to be fair, those are 2 and 3 spell levels higher than water, which means by the time it's expected a party encounters them, they'll have much more resources to deal with them.