Underwater

Underwater Rule Notes

Vision

The greatest factor that limits the underwater visual capabilities is a phenomenon known as absorption. When the eye perceives a specific color, such as the green exterior of a cloak, what it really seen is the color green reflected or radiating from the cloak. All of the other colors in the spectrum have been absorbed. The deeper light travels in water, the greater is the absorption of its constituent colors. For example, red light is almost completely absorbed by water at a depth of about 25 feet, and all of the colors of the spectrom-except blue-are absorbed at below 100 feet.
Thus absortion wreaks havoc with infravisual capabitities.
All of the particles suspended in water scatter light rays. Such rays bounce from particle to particle
until their energy dissipates completely. This scattering process severely limits the available light and, thus, the range of a surface dweller’s vision.
The following tables detail the surface dweller’s underwater vision. The tables take into account the quality of water (clear, turbid, or murky) as well as prevailing surface conditiw (clear day, ovemt,
or moonless night, for example).

Clear Water

Surface Condition	Movement	Spotted	Type	ID	Detail
Clear Day	100	80	60	40	5
Overcast	50	40	30	20	5
Stormy	40	30	20	10	5
Moonlit Night	25	25	15	10	10'
Moonless Night	15	15	5	10'	5'

Turbid Water

Surface Condition	Movement	Spotted	Type	ID	Detail
Clear Day	80	60	40	20	5
Overcast	40	30	20	10	5
Stormy	20	15	15	5	5
Moonlit Night	15	10	10	5'	-
Moonless Night	10	5	5	-	-

Muky Water

Surface Condition	Movement	Spotted	Type	ID	Detail
Clear Day	20	15	10	5	-
Overcast	15	10	5	5'	-
Stormy	10	5	5'	-	-
Moonlit Night	5	5'	-	-	-
Moonless Night	5'	-	-	-	-

Note8 to Tables 39-41
Thus, an adventurer could see 20 yards in murky water on a Clear Day.
Unless otherwise noted, all ranges are in yards.
Clear Day is the equivalent of bright sunshine and a cloudless sky.
Overcast conditions have heavy cloud cover, light rain, light to medium fog, or any other meteorological
phenomenon that blocks sunlight from penetrating the water’s surface.
Stormy conditions are the equivalent of heavy rain, heavy fog, gale force winds, blizzards, and other heavy storms. Not only do these dangerous weather conditions block sunlight, but they also stir up
sediment and other underwater debris that clouds vision.
Moonlit Night refers to clear nighttime surface conditions that allow moonlight to shine into the
water.
Moonless Night refers to cloudy nighttime surface conditions that effectively block all moonlight and
starlight from illuminating the water.
Movement is the maximum distance at which characters can spot motion underwater. Note that
characters cannot obtain any other information (that is a creature’s type or size) at this distance.
Spotted is the maximum distance at which characters can detect the presence of a stationary figure. Again, characters cannot obtain further information about the figure at this distance.
Type is the maximum distance at which characters can note the general classification (fish-like, humanoid, square) of the spotted figure or object.
ID is the maximum distance at which characters can clearly identify the spotted object or figure in question. Thus, at this distance, adventurers can identify the exact race or species of a humanoid figure. In addition, most actions can be clearly seen at this distance.
Detail is the maximum distance at which characters can see actions (including those as surreptitious as
pick-pocketing), emotions, and identifiable physical features.

Any light source that does not equal sunlight in intensity only raises the prevaibg surface condition
to Overcast within its radius. For example, the light from a phosphorescent globe (rbughly equal to
torchlight) would move the surface condition from Stormy to Overcast in a 15-foot badius.
Infravirion: In campaigns thgt use the standard infravision found in DMG, what the character sees depends on the vyater conditions as noted on Tables 39-41. Use the Overcast line on each
table. For example, if Cordwain, had infravision with a 60-foot range, he could see 15 feet underwater.

Communication

Underwater communication is a difficult task for surface dwellers, as their sensory organs are not designed for efficient underwater uae. Without magical assistance, most PCa find it difficult to convey
more than the simplest of messages while in water. A big part of the difficulty with underwater communication stems from the pmsure exerted on a surface dweller’s auditory organs. Such pressure creates a constant buzz of white noise which effectively muffles sound. Consequently, although sound waves travel almost four times faster in water than they do in air, making it easier to hear sounds at a distance, underwater pressure severely reduces a surface dweller’s capacity to distinguish these sounds.

Underwater Hearing Ranges

Noise	Unassisted Surface dweller	Assisted Surface dweller	Marine Creature
Natural Moderate Heavy Cataclysmic	300 600 900 1200	2x	10x
Speech Simple Complex	10 5' -	20 10 5	100 50 25
Surface Activity Moderate Heavy	100 200 300	2x	10x
Underwater activity Moderate Heavy	150 300 450	2x	10x

Speaking
Speaking is impossible without magical help that enables the speaker to breath air. This means the masks of No Breathing do NOT allow the people wearing them to speak. However, the guards who use the Masks are trained for years in hand and bubble speach that allows them to communicate fluently at visual distance labeled "ID". The same holds true of the Rocks of Water breathing as they only effect the area inside the mouth.

Movement
Proficient Swimmers move 1/2 normal
Non-Proficient Swimmers move Human 40' - Dwarf 30'
Movement when walking is 1/3 of normal.

Combat
+4 to Inititive
-4 to Hit

Thrown weapons such asdaggers and darts do not work underwater. In addition, normal bows and cmssbows are not effective when used underwater as their wooden components tend to warp and, in the case of crossbows, their firing mechanisms tend to rust and lock.
The DM should begin rolling for each crossbow. Roll ST vs acid each turn. A fail indicates that something bad will happen when the bow is used. Roll 1d4

String Breaks
Firing Mech. freezes
Bolt guide warps and missle goes astray. Use gernade misses table to determine direction.
Firing Mech. snaps weapon useless.

The Corp of No Breathing use specially constructed crossbows that are designed to work underwater. These are constructed entirely of wood, with the exception of parts of the firing mechanism which is made of a specially strengthened ceramic. The bolts are 1/2 the length of a normal sheif arrow, have not flights and are thicker. Also, they are weighted with strips of thin lead precisely along their length. They are specialized in this weapon, and so are only a total -1 to hit with it.

Those proficient in Underwater Combat skill (as are the Corp of No Breathing) only suffer a +2 to inititive and a -2 to hit roll.

Damage
Use the special weapon damage table on page 83 of Ships and the Sea book.