Water, Water Everywhere . . .

[L. Marcus]

. . . How much protection do you figure it gives? I was just thinking of the D-Day scene from Saving Private Ryan, and the "Over the sides!" bit, and then there was the German bullets flying through the water . . .

 

. . . And I wondered how much rPD an Hero inch of water have. I'm that weird.

[Edsel]

Re: Water, Water Everywhere . . .

 

At sea level, air is 784 times less dense than water. This means that a bullet should have its range cut to 1/784 normal when it hits water. That is why bullets slow down so quickly in water.

 

Granite = 2700 kg/cu. meter density.

Fresh water = 998 kg/cu. meter density.

Sea water = 1025 kg/cu. meter density.

 

So roughly water is about 1/3 the density of stone. If you want to simulate the effect of the water's surface tension (as DEF) against high speed projectiles it'd probably be about a 2 DEF. The the water will absorb body equal to about half that of stone. I'd look at the table on page 448 of 5ER and half the stone values for water.

 

NOTE this is all just a wild a-s guess for the most part.

[MadCatBob]

Re: Water, Water Everywhere . . .

 

Well, angle of entry factors aside, the Mythbusters fired several guns at an angle into a pool and found that you're safe at around 3 to 5 feet from even a .50 cal rifle. So, offhand, I'd say somewhere from (Edit) 4-6.

 

Edit: Assuming, though, that you are not in the inch, but under it.

[ghost-angel]

Re: Water, Water Everywhere . . .

 

Would it supply defenses or simply drastically reduce range?

[Steve]

Re: Water, Water Everywhere . . .

 

I suspect this would be one of those cases where the failure to do damage is more from a defense effect than an aiming effect, which is how range modifications would come into play. I'd be good with doing it as a defense boost as a GM.

[schir1964]

Re: Water, Water Everywhere . . .

 

Perhaps water or similar substances should impose the "Explosion" rules to any damage that passes through them?

 

- Christopher Mullins

[Teflon Billy]

Re: Water, Water Everywhere . . .

 

Well, angle of entry factors aside, the Mythbusters fired several guns at an angle into a pool and found that you're safe at around 3 to 5 feet from even a .50 cal rifle. So, offhand, I'd say somewhere from (Edit) 4-6.

 

Edit: Assuming, though, that you are not in the inch, but under it.

This would indicate the effects seen in Saving Private Ryan were grossly off, they had soldiers getting hit at some points by bullets going through 6-8' of water.

 

TB

[pinecone]

Re: Water, Water Everywhere . . .

 

An easy aproximation would to aply reduced by range, with one "penalty reduction" so water give a mild defense and lotsa water is a solid defence...

 

 

Or...do like me and hand wave stuff..."Lets reverse the polarity!"

[Robyn]

Re: Water, Water Everywhere . . .

 

A bullet doesn't have to pass through an entire hex of water, just one small part of it, but you might be able to derive some PD/rPD from the BODY rating for water. A few threads discuss this:

 

Water Weight

Body of question

Spell build help needed: Transform + AOE

[Markdoc]

Re: Water, Water Everywhere . . .

 

This would indicate the effects seen in Saving Private Ryan were grossly off, they had soldiers getting hit at some points by bullets going through 6-8' of water.

 

TB

 

Good heavens, you mean that Saving Private Ryan wasn't completely accurate? (Throws up hands in shock and horror!)

 

OK, I enjoyed the movie more than I thought I would, but still, I also noticed the bullets zipping through the water in the first scene and thought "That's not right". There were a number of glitches, mostly to do with equipment, that you can pick up, some of which were made deliberately, for "effect". I guess (I hope) the bullets were done for the same reason.

 

cheers, Mark

[BNakagawa]

Re: Water, Water Everywhere . . .

 

This would indicate the effects seen in Saving Private Ryan were grossly off, they had soldiers getting hit at some points by bullets going through 6-8' of water.

 

TB

 

They might have been machinegun bullets. I don't think the mythbusters tested machineguns.

[lemming]

Re: Water, Water Everywhere . . .

 

They might have been machinegun bullets. I don't think the mythbusters tested machineguns.

Well, according to a previous post they tested .50 cal. Which granted was one of the US weapons. According to the net, the MG-42 was a 7.92mm. Higher ROF, but less penetration.

[Vondy]

Re: Water, Water Everywhere . . .

 

They might have been machinegun bullets. I don't think the mythbusters tested machineguns.

 

A .50 BMG only has an effective water penetration to a depth of 12-14". That's fresh water; salt water is somewhat more resistant and might reduce its effective penetration depth even more. The machineguns favored by the wermacht, including the ones used at Normandy, were chambered for 7.62, 7.92, and 8mm - about .30 caliber.

 

Machineguns (all guns, really) are designed to penetrate solids; liquids screw everything up. And its not just the liquid medium; surface tension is a ballistic nightmare, especially when you factor angles in. Lower velocity bullets have been known to richochet when hitting water at a weak angle, like rocks when you skip them.

 

EDIT: Also, most bullets adopt an increased downward trajectory in water - "drift" is dramatically increased in water.

 

Von "the benefits of an otherwise useless criminology degree" D-Man

[gojira]

Re: Water, Water Everywhere . . .

 

Well, angle of entry factors aside, the Mythbusters fired several guns at an angle into a pool and found that you're safe at around 3 to 5 feet from even a .50 cal rifle. So, offhand, I'd say somewhere from (Edit) 4-6.

 

Edit: Assuming, though, that you are not in the inch, but under it.

 

 

Based on this, I'd rule that water gives you 3 to 5 rDEF per foot until you are at 15 rDEF, then you are "out of range." For games, I'd probably break it up into:

 

1. Close to 90 degrees angle of entry: 3 rDEF per foot of water

 

2. Close to 45 degree angle of entry: 4 rDEF per foot of water

 

3. Close to 20 degree angle of entry: 5 rDEF per foot of water

 

And less than 10 degrees means the bullet skips and you are out of range, period.

[AmadanNaBriona]

Re: Water, Water Everywhere . . .

 

They might have been machinegun bullets. I don't think the mythbusters tested machineguns.

 

They tested a .50 Caliber sniper rifle which uses the same cartridge as the M-2HB, so for all intents and purposes they did (They, BTW, were half expecting to crack the pool, and were suprised to discover that the .50 was just as lousy at penetrating water as the smaller rounds). The one that did the best, IIRC, was the black powder musket... a large lead ball moving at subsonic speeds. That "subsonic" bit seemed to be the sticking point... all the supersonic rounds (basically all the tested modern ammo) shattered upon impact with the surface of the water and the fragments expended their energy very quickly. The conclusion was that around 5 feet worth of water would protect you from almost any small arm, and unless the shooter was shooting down into the water from an elevated position, the angle of fire is such that even 2-3 feet would provide cover in most situations.

[Sir Ofeelya]

Re: Water, Water Everywhere . . .

 

The Mythbusters show showed that lower velocity rounds went deeper. They firied a Civil War era Springfield rifled musket into water and the round penetrated their ballistic gel at about 2-3 metres depth. Small handguns did the same. .30 and .50 cal rounds actually disintegrated into tiny pieces of lead.

 

EDIT: I just read the post above which already pointed out the fcats I alluded to.

[Robyn]

Re: Water, Water Everywhere . . .

 

At sea level' date=' air is 784 times less dense than water.[/quote']

 

You (and those following the thread) may be interested in this older thread covering the mass, BODY, and weight of air; asking about the DEF and DCV of air; and a formula showing the density of air at sea level and higher altitudes.

[BNakagawa]

Re: Water, Water Everywhere . . .

 

IIRC, the DDay landing took place at low tide so that the submerged obstacles would be visible.

 

This means that the soldiers in the water are quite a bit further away from the defenders than they might be at high tide. (depending on the slope of whatever beach they are landing on)

 

Also, as I recall, the bullets shown are coming in at a pretty steep angle, which would be impossible if fired directly at them because the bluffs are not high enough to get such an angle. (even more so at low tide)

 

So, it is possible that some men who went underwater might have been struck by bullets fired from a considerable distance that were angled steeply downwards due to gravity, as they were nearly but not quite spent. This might also have reduced their velocity to subsonic speeds which would also help in penetrating the water.

 

So, it is possible, although highly unlikely that some soldiers were shot in a fashion as shown in the movie Saving Private Ryan.

[Mike W]

Re: Water, Water Everywhere . . .

 

Well, angle of entry factors aside, the Mythbusters fired several guns at an angle into a pool and found that you're safe at around 3 to 5 feet from even a .50 cal rifle. So, offhand, I'd say somewhere from (Edit) 4-6.

 

Edit: Assuming, though, that you are not in the inch, but under it.

 

I remember that. The angle of entry is critical. Fired straight down, the water does almost nothing to slow the bullet. On a more realistic angle(say 30 degrees or so) the water was actually breaking up modern high speed bullets within about 3-5 feet. As in, Adam was fishing the bullet fragments off the bottom of the pool while the target was unharmed.

[Frenchman]

Re: Water, Water Everywhere . . .

 

So, I'm hearing that <1" of water provides signifigant protection, while >1" makes bullets almost useless. So if you're interested in that kind of realism, then how about 50% damage reduction if a target is within 1" of the surface, and complete protection if they are deeper than that.

Alternately, you could say that each 1" of water halves the DCs of the attack, which would allow very large attacks to penetrate deeper.

Also - does this only apply to bullets? I'm getting that vibe from the comments so far. What about other types of attacks? I'd be inclined to say that any attack would function like this against a target in water unless it is specifically meant to be used underwater.