Cerulean Seas Underwater Perils

The sea holds many dangers that an unwary adventurer might encounter. Below are listed a few of these insidious hazards.

## **DISEASE**

The sea hosts a myriad of common diseases that plague its citizens and infest the unfortunate. A sampling of these diseases can be found below.

### **FIRE CORAL**

**Type** disease, injury; **Save** Fortitude DC 12

**Onset** 1d4 rounds; **Frequency** 1/day

**Effect** 1d3 Dex damage and victim does not heal or regenerate naturally; **Cure** 2 consecutive saves

### **ICK**

**Type** disease, contact, inhaled, injury; **Save** Fortitude DC 16

**Onset** 1d3 days; **Frequency** 1/day

**Effect** 1d4 Cha damage and victim is continuously fatigued;

**Cure** 2 consecutive saves

### **SEA ROT**

**Type** disease, injury; **Save** Fortitude DC 18

**Onset** 3d4 days; **Frequency** 1/day

**Effect** 1d4 Dex damage and 1d2 Cha damage; **Cure** 3 saves

### **TAPE WORM**

**Type** disease, ingested; **Save** Fortitude DC 16

**Onset** 2d6 days; **Frequency** 1/week

**Effect** 1 Con damage, target must make a second Fort save or damage is drain instead; **Cure** 3 consecutive saves

### **WHITE SPOT**

**Type** disease, contact, injury; **Save** Fortitude DC 12

**Onset** 1d3 days; **Frequency** 1/day

**Effect** 1d4 Str damage and 1d4 Cha damage; **Cure** 2 consecutive saves

## **POISON**

Poison of the sea usually derives from its more toxic denizens, of which there are plenty. Inhaled poisons are absorbed through gills or glungs; creatures without those features are immune while submerged.

### **BOX JELLY TINCTURE**

**Type** poison, contact; **Save** Fortitude DC 22

**Frequency** 1/round for 4 rounds

**Effect** 1d8 Con damage and paralyzed for 6 rounds

### **CONCH EXTRACT**

**Type** poison, injury; **Save** Fortitude DC 18

**Onset** 1d3 rounds; **Frequency** 1/round for 4 rounds

**Effect** 1d3 Str damage; **Cure** 2 saves

### **LIONFISH VENOM**

**Type** poison , injury; **Save** Fortitude DC 16

**Frequency** 1/round for 3d4 rounds

**Effect** 1 Str damage; **Cure** 3 consecutive saves

### **OCTOPOSION**

**Type** poison, injury, inhaled; **Save** Fortitude DC 13

**Onset** 5 minutes; **Frequency** 1/minute for 5 minutes

**Effect** 1d4 Wis damage and 1 Dex damage; **Cure** 2 saves

### **PUFFER TOXIN**

**Type** poison, ingested; **Save** Fortitude DC 15

**Onset** 15 minutes; **Frequency** 1/hour for 24 hours

**Effect** 1d6 Con damage and nauseated for 24 hours, missing two consecutive saves causes victim to be paralyzed for 1d4 hours (cumulative)

### **SEA SNAKE VENOM**

**Type** poison, injury; **Save** Fortitude DC 26

**Frequency** 1/round for 5 rounds

**Effect** 1d4 Str damage

## **BLOOD IN THE WATER**

Sharks can detect one drop of blood in twenty- five gallons of water and can sense even tiny amounts of blood in the water up to three miles away. It can be assumed that many other sea creatures have similar talents. Since underwater combat almost always yields copious amounts of blood in the water, this can serve as a beacon for predators and scavengers.

## **FRESHWATER**

All of the races in the Cerulean Seas setting are adapted to saltwater, which comprises over 99% of the water on the planet. However, freshwater does exist in isolated pockets from natural springs, river deltas, melting ice, and even inland lakes. When any native of the Cerulean Seas becomes fully immersed in freshwater, it must succeed on a DC 15 Fortitude save or become fatigued. Even on a success, it must repeat the save attempt every 10 minutes it remains immersed.

## **HYPOXIC ZONES**

Also known as “dead zones,” these are particularly oxygen depleted areas of the sea. They can range in size from a few hundred feet to several miles in diameter. They have a variety of causes, including pollution, algae or bacterial bloom, or even magic. Hypoxic zones are most often temporary, lasting a few days or weeks. Permanent hypoxic zones also exist, however, and are often well- marked by the local denizens to warn travelers not to enter.

Regardless, a hypoxic zone has a distinct lack of natural life in the area. Undead often plague these regions, as they do not need to breathe and can lair there unmolested. Characters entering such a zone immediately begin drowning unless they have the “hold breath” special quality.

## **METHANE BUBBLES**

Natural methane gas routinely bubbles up from the seabed in locations all around the sea. Normally, this is a passive occurrence. However, every now and then the quantity of methane can be vast. This is typically a very localized phenomenon, rarely exceeding 50 feet in diameter.

Methane bubbles of this magnitude create two distinct hazards. First, the fizzy bubbles immediately reduce the density of the seawater in which this occurs. This, in turn, drastically reduces the buoyancy of objects and creatures moving through this water. Refer to Table 1-11 to determine how much negative buoyancy the creature is affected with while swimming in this area.

 Diminutive
 Tiny
 Small
 Medium
 Large
 Huge
 Gargantuan
 Colossal

The second hazard is that methane is explosively flammable. Since fire is seldom used by sea denizens, this shouldn’t be an issue unless lightning is involved. Lightning or fire damage, either mundane or magical, will immediately ignite the methane, causing an explosion that does 10d10 heat damage to all within three times the area of the methane bubbles. The surface of the water will then be on fire until the methane dissipates (at the GM’s discretion) or 1d6 days, whichever is shorter.

## **MURK**

Water containing a lot of debris, sediment, or algae is considered murky. Much like a fog, murky water reduces the radius of illumination provided by a light source by half. Extremely murky water obscures all sight, including darkvision, beyond five feet. Creatures five feet away have concealment.

## **RED TIDE**

Red tide is a phenomenon caused by algal blooms in which algae become so numerous that they tint coastal waters a reddish-brown and fill the area with heavy murk. At night, crashing waves on affected water flash with visible neon-blue light. While the nocturnal effects of this peril can be breathtaking, the real hazard is that these algae are highly toxic. Each round that a creature stays within waters affected by red tide, that creature must make a Fortitude save, DC 12, or take one point of Constitution damage. Red tide kills most wildlife that encounters it, causing a massive rotting stench that may attract scavengers similar to those that frequent areas of thick sargassum. Red tide usually affects several miles of coastline in long strips that start at the shoreline and are 1d10 × 100 feet wide. All of the water in this area is affected. Red tide can last days, weeks, or even become an annual or permanent feature.

## **WHIRLPOOLS**

A whirlpool is a swirling body of water typically formed by ocean tides. Most whirlpools are not very powerful, nor particularly long lived. More potent ones are more appropriately termed maelstroms, and can be permanent fixtures of the sea. While very powerful whirlpools are created in narrow shallow straits with fast flowing water, the most powerful maelstrom are formed near portals to the Elemental Plane of Water.

Before the great flood, seven gigantic maelstroms once existed that were named the “Portals of Oblivion.” When the landfolk destroyed these features in their rebellion against divinity, the flood began. It has been speculated that these maelstroms were actually enormous drains that led to some other plane of existence. This does not explain where the water came from, however, or why the flood eventually stopped even though the whirlpools were never reinstated.

Whirlpools come in one of four sizes: vortex (10 to 50 feet in diameter), standard whirlpool (51 to 100 feet in diameter), maelstrom (101 to 500 feet in diameter), and greater maelstrom (501 feet to 2,000 feet in diameter). Whirlpools are typically as deep as they are wide.

Whirlpools are surrounded by strong feeder currents that can draw in swimmers far from the whirlpool itself. These currents work like strong water currents that always move towards the center of the whirlpool. The speed of a feeder current immediately next to a maelstrom is 120 feet. This speed is divided in half at each range increment from the center of the maelstrom. Table 1-12 describes the length of each range increment based on the size of the whirlpool. The current is generally negligible if its speed is less than five feet.

 Standard
 Maelstrom
 Greater

For example, a feeder current that exists 950 feet from the center of a maelstrom moves at a speed of 15 feet, while a greater maelstrom’s feeder currents at the same distance would still have a speed of 120 feet.

Once a swimmer is sucked into the whirlpool by the feeder currents rushing toward it, the victim becomes hopelessly trapped. During each round of being trapped the victim takes bludgeoning damage from being violently whipped around and battered. Table 1-12 indicates the number of rounds trapped and the bludgeoning damage for each round that the victim is trapped, based on the size of the whirlpool.

A vortex can only trap objects or creatures of Huge size or smaller. Gargantuan-sized creatures or greater cannot be trapped by standard whirlpools. Maelstroms and greater maelstroms can trap creatures or objects of any size.

At the end of being trapped, the victim is propelled at a speed of 120 feet through the bottom of the whirlpool. This could be the equivalent of being violently shoved to the sea floor, squeezed through a hole in the bottom of the ocean, or punted into the Elemental Plane of Water— depending on what the Gamemaster decides is at the bottom of this terrible peril.