Does water provide cover?

[Red Bear]

if possible I'm looking for a RAW answer in general about water and cover and specifically about the ability "seeking arrow" of the arcane archer fighter subclass, would it work if the target is underwater?

Probably there isn't a RAW answer so I'm also interested in how you would rule

[nickl_2000]

So the most RAW answer I can give would be based on the Wall of Water spell.

A 1 foot thick wall of water gives disadvantage on all ranged weapon attacks. It says nothing about giving cover for a bonus to AC and doesn't stop ranged spell attack damage.

From a physics standpoint, according to this site http://kwc.org/mythbusters/2005/07/mythbusters_bulletproof_water.html when a bullet is travelling at a 30 degree angle you only need to be 3 feet underwater to be completely safe from a bullet. An arrow or sling stone is less aerodynamic (well hydrodynamic) than a bullet and isn't fired as powerfully (according to quick research an arrows initial velocity is around 400 feet per second, where as a bullet can easily be over 2000 feet per second).

Overall, I would say that 1 foot of water imposes disadvantage (per RAW wall of water spell) and 2 feet of water completely protects you from ranged weapon attack (per physics and houserule). However, you can still see someone under clear water so I would allow ranged spells attack per normal. A seeking arrow requires that someone be within the range of an arrow and my ruling would be that over 2 feet of water would outside of an arrows range, also there is no legitimate path to the target as seeking arrow requires.

Now piercing arrow would be fine against someone under water since it "passes harmlessly through objects"

[Kadesh]

There is a dragon in a Yawning Portal adventure who gets 3/4 Cover with his head exposed from the water, but body below.

[N810]

While water is excellent cover against small fast objects, (bullets)
it is less effective against slower heavier objects. (arrows)
[see bow fishing]

[Ganymede]

The Underwater Combat section of the PHB doesn't say anything about all underwater targets getting cover all the time.

[dejarnjc]

How many feet would it take to be safe from an arrow in real life ?

[Unoriginal]

Depends how well you can see through the water.

[dejarnjc]

Depends how well you can see through the water.

I just mean in terms of slowing down the velocity of the arrow.

[willdaBEAST]

Depends how well you can see through the water.
There are also elements like refraction of light, you may be aiming slightly off target due to how light bends in different mediums.

I think something to simplify the real world physics makes sense. 1/2 or 3/4 cover if the target is barely submerged in relatively translucent water, disadvantage if they're significantly submerged or in murky water and the ranged attack automatically misses if they're submerged past some arbitrary depth of water.

https://adventure.howstuffworks.com/outdoor-activities/hunting/traditional-methods/bowfishing2.htm
Here's a resource on real world bowfishing. It not only touches on how specialized targeting something in water is due to the refraction, but also seems to suggest beneath 4 ft, the density of water (compared to air) is going to slow down the projectile.

[Vogie]

The Underwater Combat section of the PHB doesn't say anything about all underwater targets getting cover all the time.

It wouldn't provide cover if both people were in water at equal level, as an normal undersea fight would be.

But going from the air, firing into the water... there light refraction, and a literal barrier of water in the way.

To be honest, I'd probably provide the same benefit of a Wall of Water if someone was standing (laying?) behind at least 1 foot of it. This would give:

Difficult Terrain when entering
Disadvantage on Ranged weapon Attacks going through
Fire Effects that travel through it have damage halved
Cold spells cast through the water cause the water to freeze in 5ft squares

[Unoriginal]

Most Cold-damage dealing spells do not have a freezing effect. The ones who do have it precised.

[Hecuba]

if possible I'm looking for a RAW answer in general about water and cover and specifically about the ability "seeking arrow" of the arcane archer fighter subclass, would it work if the target is underwater?

Probably there isn't a RAW answer so I'm also interested in how you would rule

To borrow a phrase from a linear algebra professor I hated with a passion way back in college (when dirt was young): "The remainder of the example is left as an example to the reader."

To the best of my knowledge, water is not called out in any general case of providing or not providing cover.

If you extrapolate from the real world, it should generally do so for most purposes after a handful of meters at most.
If you extrapolate from the underwater combat rules and the existence of aquatic races, it shouldn't - but you do have to extrapolate: there is no explicit handling of the situation you describe.

For most purposes I would go with saying it does not give cover in the general case - otherwise you're on the hook for redesigning underwater combat.

[Vogie]

Most Cold-damage dealing spells do not have a freezing effect. The ones who do have it precised.

As I mentioned, that text is from the spell Wall of Water (originally in Elemental Evil):


Spells that deal cold damage that pass through the wall cause the area of the wall they pass through to freeze solid (at least a 5-foot square section is frozen). Each 5-foot-square frozen section has AC 5 and 15 hit points.

[Unoriginal]

As I mentioned, that text is from the spell Wall of Water (originally in Elemental Evil):

And that's a spell itself, which reacts like that to cold spells.

Ray of Frost has no effect on normal water, for example.

[Vogie]

And that's a spell itself, which reacts like that to cold spells.

Ray of Frost has no effect on normal water, for example.

By RAW that's right. Nor would 1 foot of water do any of the other things that I mentioned, such as halving fire damage and providing disadvantage on ranged attacks.

That's precisely why I said that I'd use those effects as a jumping-off point for this argument... because those rules aren't in RAW.

[Demonslayer666]

As DM, it would depend on the amount of water. If there is a lot, I would restrict the range like underwater combat. Other than that I would allow it to function as normal.

[N810]

How many feet would it take to be safe from an arrow in real life ?

(assuming your attacker is firing from above the water. )
I would guess 1/2 cover for 5' and 3/4 for 10' ?

[Hecuba]

https://adventure.howstuffworks.com/outdoor-activities/hunting/traditional-methods/bowfishing2.htm
Here's a resource on real world bowfishing. It not only touches on how specialized targeting something in water is due to the refraction, but also seems to suggest beneath 4 ft, the density of water (compared to air) is going to slow down the projectile.

If you're looking for verisimilitude rather than easy of running the game, this isn't a bad place to start. Spearfishing (without a modern harpoon gun) is also a good place to look. In general: if you're spearfishing for something at ~30 ft./10 meters, you're diving down to do it. And trying to spear something 30 ft away isn't where accuracy starts to suffer (i.e. - the beginning of long range in game terms) - it's closer to the limit of how far you can reach at all (i.e. the maximum side of long range in game terms). In contrast, the javelin (which the game uses for the thrown spear) is a 30/120 weapon in air.

[Oramac]

From a physics standpoint, according to this site http://kwc.org/mythbusters/2005/07/mythbusters_bulletproof_water.html when a bullet is travelling at a 30 degree angle you only need to be 3 feet underwater to be completely safe from a bullet. An arrow or sling stone is less aerodynamic (well hydrodynamic) than a bullet and isn't fired as powerfully (according to quick research an arrows initial velocity is around 400 feet per second, where as a bullet can easily be over 2000 feet per second).


While water is excellent cover against small fast objects, (bullets)
it is less effective against slower heavier objects. (arrows)
[see bow fishing]

Indeed. Plus, bullets are designed to deform upon impact, including impacts with water. Arrows, OTOH, are not (outside of specific broadhead hunting designs). Therefore, I would rule that arrows can pierce water to a much better depth, though still not much.

I think DA on the attack roll would simulate it well enough.

[ImproperJustice]

Alternatively, it’s a magical arrow fired by a magical archer at an opponent where a clear path exists.

IMHO a seeking arrow should strike through water, hedges, arrow slits, and high winds.

That just seems like the point was of the ability to me.

[Kane0]

Under normal circumstances, i'd rule a few feet of water constitutes half cover and a few dozen feet three quarters cover. If the depth is so great you cannot see your target that's effectively full cover, but range would typically be a bigger problem at this point.
Seeking arrow ignores cover, so no issue going through water.