Underwater dwellers and pressure damage

[LGodamus]

I wouldnt do all aquatic as immune.....I would do something like any aquatic sub type with CON20 or DR5 or more that way hardy monsters would be able to live at depth ..monsters like the kraken and Dire sharks and what not but not sea elves and other monsters that normally would stay shallow.

 

[Norfleet]

Pressure isn't really harmful unless it changes rapidly, or the creature in question contains a pressure difference. Pressure is only potentially damaging if a creature contains an environment of a different pressure, which causes force to be applied to creature. Thus, it's possible for humans to actually dive fairly deeply with scuba equipment, because the scuba equipment feeds pressurized atmosphere to offset the external pressure of the water. Submarines, on the other hand, can be crushed by pressure because they contain a standard-pressure atmosphere internally, and thus a large pressure difference can build up between the inside and outside of a submarine. Squid, on the other hand, can survive both deep and shallow water because their bodies don't have this internal pressure problem: They lack bones, lungs, or any other systems that induce a pressure difference. Con, and Fort saves, are entirely irrelevant to how it works. It should be noted that the atmospheric pressure at the Earth's surface is actually very strong and crushing! All you have to do to see this is to suck the air of a pop can, and watch as the pressure causes it to instantly implode. Yet people feel nothing, because their internal body pressure is the same as the atmospheric pressure.

Therefore, a Sahuagin or Aquatic Elf would survive just fine in the depths. If you suddenly teleport one from the bottom of the ocean to the surface, however, it will instantly explode. If you teleport one from the surface to the bottom of the ocean, it will be immediately crushed. If it travels naturally at a pace it deems comfortable, then it will be fine.

 

[Vysirez]

Therefore, a Sahuagin or Aquatic Elf would survive just fine in the depths. If you suddenly teleport one from the bottom of the ocean to the surface, however, it will instantly explode. If you teleport one from the surface to the bottom of the ocean, it will be immediately crushed. If it travels naturally at a pace it deems comfortable, then it will be fine.

I just had this amusing thought of a wizard summoning some aquatic monster info a fight only to have it explode.

 

[LGodamus]

norfleet what you say is true only to a certain extent ..
most shallow water fish cannot survive in the deep...its a simple fact, there is no reason an elf would be able to either..........besides people cannot dive all that deep with scuba gear on....if you will check free diving records you will see people without scuba gear can reach much greater depths.......and those free divers will tell you that the pressure exerted on their bodies is immense and if they were not very healthy and well trained it could well kill them.

 

[dark2112]

Interest in the giant squid tends to result in some pretty large leaps in logic when discussing the creatures. It is unclear that sperm whales (that rarely go below 350 meters) actually feed on live giant squid (which live at depths in the thousands of meters).

"The deepest dive by a mammal was made by a bull sperm whale (Physeter macrocephalus) off the coast of Dominica, in the Caribbean, in 1991. Scientists from the Woods Hole Oceanographic Institute recorded the dive to a depth of 2,000 m (6,500 ft)."

And...

if you will check free diving records you will see people without scuba gear can reach much greater depths

"The record depth for the dangerous sport of no limits free diving by a woman is 125 m. (411 ft.) by Audrey Mestre Ferrera at La Palma, Canary Islands, Spain on May 13, 2000."

I dunno... I heard mention of 300 meters above, but I'm no SCUBA expert. I have no idea how deep you can actually dive in SCUBA gear.

Note: Both quotes come from http://www.guinnessworldrecords.com

 

[LGodamus]

"The deepest dive by a mammal was made by a bull sperm whale (Physeter macrocephalus) off the coast of Dominica, in the Caribbean, in 1991. Scientists from the Woods Hole Oceanographic Institute recorded the dive to a depth of 2,000 m (6,500 ft)."

And...



"The record depth for the dangerous sport of no limits free diving by a woman is 125 m. (411 ft.) by Audrey Mestre Ferrera at La Palma, Canary Islands, Spain on May 13, 2000."

I dunno... I heard mention of 300 meters above, but I'm no SCUBA expert. I have no idea how deep you can actually dive in SCUBA gear.

Note: Both quotes come from http://www.guinnessworldrecords.com

for scuba the normal max depth is 130 ft. but the world record with special gear is just over 300m.

 

[Keith]

Whatever the gear involved in a dive, none of it in fact has anything at all to do with direct pressure on the body, pretty much as Norfleet alluded to above. Yes, descent and ascent speeds are crucial.
The difficulties are with breathing.
Provide a spell for that, and the human body could survive the pressure at a rather surprising depth. Yes, over three hundred meters is the record for diving with gear at the moment. Again, though, the actually pressure at that depth causing damage is not even a remote consideration- it is a non-issue.
So, a system that starts damaging people at below 100 feet (where recreational divers can routinely be found, not suffering pressure damage) is not one that is based on much familiarity with how the body actually reacts to depth pressure. Someone just took a shot in the dark, and missed badly, with that figure.

 

[Tonguez]

I have a WhaleRider PrC IMC which gains the Aquatic subtype at level 10 one of the class abilities is to not take damage due to deep water (the other is to able to breath underwater)

So IMC I've rules that Aquatic Subtype means no damage due to deep water

Really the only time this is going to be an issue is when your PCs are underwater fighting aquatic creatures or ARE aquatic creatures themselves

 

[Aeolius]

In my undersea campaign, I do not allow most of the PCs to freely travel into the depths, without some form of protection from the pressure and chill of the deep, unless they have an elemental component such as with a triton or half-elemental or are related to a race known for adventuring in the deep, i.e. a half-kraken.

I also placed several races in the darkness of the depths, such as kolocanth (sea bugbears), abyssal elves, and water dwarves. The latter dwell near hydrothermal vents, have red skin, are chemosynthetic, and are not to be confused with the aquatic dwarves in Unearthed Arcana. My aquatic orcs, goblins, and kobolds are different as well - but that's a different story

 

[green slime]

These rules concerning "pressure damage" are ludicrous at best.

As Keith and Norfleet have described.