Help me understand how the game works when I'm in water

[Human Fighter]

Okay, so let's say I'm in water with my head above so I can breathe. I had a game where the GM ruled that my head was actually in the above square, thusly a swarm of bates had full access to just eat away at me.

Also, what sort of action do you think it is to put your head above and below the threshold of the top of the water? I had an issue that I needed to move 5 ft up to not really move 5 feet up at all, but to just get my head out to breathe. This was very frustrating, and to me it makes sense that I occupy the 5 ft cube and can as long as I'm not sinking can at will on my turn choose to have my head above or below as a free action.

Are there rules written about this, or if not, could people give me their thoughts, please?

[Bob Bob Bob]

The rules are that you have to Swim. Yes, this Swim and not any other swim you might be thinking of from real life. The rules are assuming you want to live and so always have at least your head out of the water, if you want to go underwater you need to actively choose to swim (move action for 1/4 speed or full round for 1/2 speed) that way or fail your Swim check by 5 or more. "If you fail by 5 or more, you go underwater."

Now, all that being said, water is fairly protective.

d20pfsrd wrote:

Attacks from Land: Characters swimming, floating, or treading water on the surface, or wading in water at least chest deep, have improved cover (+8 bonus to AC, +4 bonus on Reflex saves) from opponents on land. Land-bound opponents who have freedom of movement effects ignore this cover when making melee attacks against targets in the water. A completely submerged creature has total cover against opponents on land unless those opponents have freedom of movement effects. Magical effects are unaffected except for those that require attack rolls (which are treated like any other effects) and fire effects."

This would help protect you from bats but wouldn't help you against a bat swarm because it never has to make an attack roll. So hold your breath, swim straight down, and hope they're not willing to trying swimming after you.

[Human Fighter]

Bat swarm needs to be in my square to attack me, so due to their creature size and swarm traits they can't attack a creature that's in the water correct due to not being able to get into that square?

If I want my head under water do I need to swim 5 ft down, or what kind of action is it?

[Redneckdevil]

When u are floating with ur head above water, the swarm can still attack u unless u use a move action to swim down. When in water its best not to think of the top of the water as the bottom of the square...i know i know its gets a bit technical.
or to make it easier, think of it as having ur head sticking out of a wall. Ur bodys is in the wall and protected from attacks but they can still attack u because ur head is out though u are harder to hit, it is still possible to harm and hit u.
or think a 5ft square as a cube that is 5ft all around and up and down from where ur body is, not the top of the water.

[The Terrible Zodin]

Everybody can hold their breath for rnds = 2*Con score (-1 rnd for every standard or full round action).

So take a breath, go underwater and stay there. 2-3 minutes later take another breath. Eventually the bats will kill you or go away. Or you will find a third solution.

One point of note: things are done by rounds in pathfinder. This means that for a particular round you are either underwater completely or you are not. So you will have to suck up damage those rounds that you breathe.

[Human Fighter]

Zodin, that was the plan.

Redneck, I don't see your point. By RAW you occupy a 5 ft square as a medium sized creature. You're in the water, and are getting those cover bonus' for having your head out. The bat swarm doesn't have a swim speed, and can't reach to make a attack roll into your space. The Bat Swarm can't attack people in a square of water like this by the rules. Can anyone argue otherwise with rules? I understand that it makes sense that to breathe and stuff, your head is sticking out, but how rules work you got to deal with it that the swarm can't enter your square to mess you up.

[Redneckdevil]

Its the same rules as wading thru a swamp. Is the square on top of the swampy marsh ur wading thru since the water is 2 ft deep or is the square where ur feet is at on the top o the swampy water?
granted on land its preordained, but when u get to water and air squares arent exactly defined where and when the square begins and ends as far as from up and down.
also id imagine the game sees u as floating like with ur arms and shoulders and head out of the water and not just ur face outta water..

[Bob Bob Bob]

Nothing stops a swarm of bats from flying down into the water. It doesn't have to have a swim speed to swim. How this works with failed swim checks and swarm damage I don't know, but as written it still automatically hits everything in its space, even if it's drowning.

As to the exact cube mechanics, that's an abstraction of movement that's fairly poorly covered in this case. You (the player) are likely treating your 5 foot cube as 4 feet of water down and a foot of air (for your head). The bat swarm would get the most benefit from treating it as 5 feet of air with your head in it. So we either have to have a universal grid and the bat has to swim into the water to get you or we have a personal grid and the bat can choose to target just your head (but you always can swim with just your head above the water).

[Human Fighter]

I was just having this conversation about swamp situation. You're referring to bog terrain, and depending on the depth then you're entering an even more unique situation. The swarm needs to occupy the square if I recall correctly, and if it's 4 ft of bog that includes an optional swim and gives you that cover, then a swarm without a swim speed I see has having issues. Anyways, you're still within that 5 ft square, and something needs to threaten to swing into it, or in the case of the swarm, move into it. Your head being above the threshold of water to explain the mechanics of you breathing doesn't make you occupy more than one square.

So, away from the bog again. You're within the water square and the swarm is not in your square to go off, thus it cannot harm you until it finds a way to do so.

If anyone can argue otherwise I would like to know, because I do find it to be interesting and silly that the rules work this way.

[Human Fighter]

Well we're talking about 5ft square mechanics, but you're right on the game explaining how a flying swarm like this can do swim checks and occupying such a square, Bob. I say if the swarm wanted to attack the player within the water, the swarm would need to absolutely go into the square and be in the water with the player. You can't just occupy the square above and say you're hitting the player.