The Underwater District location was discovered in 1495 DR after strange disappearances and theft, followed by attacks from Water Elementals overwhelmed the town of Hawthorne. Many groups of adventurers were involved in solving the mystery. After all was said and done, it was discovered that a Morkoth who had gained control of its island was responsible for the disappearances and the theft. Its island was hidden in a cave underneath Hawthorne. The Morkoth had positioned its island just above the waterline in the cave, and had found a way to magically connect its island to Hawthorne in a way that would allow it to steal people and objects from the town. The Water Elementals were due to Sultan Rezzo the Marvelous’ attempt to retrieve some artifact that had been stolen from him in the past by the Morkoth.
An alliance was forged between the Sultan and the guild, and the guild sent a group of adventurers to deal with the Morkoth once and for all. They weren’t able to defeat the Morkoth, but they were able to drive it away and to recover the missing persons and the Sultan’s artifact. As a token of his gratitude, the Sultan has agreed to allow safe passage in the portal leading to the Elemental Plane of Water that was found in the cave underneath Hawthorne and which led near the Sultan’s palace. In order to expand the town, enhance its safety and to allow for its amphibious citizens to have an underwater home, the Hawthorne Guild gathered resources and worked to establish a new residential district in this underground cave, now known as the Underwater District.
The entrance of the cave is located about 500 feet underwater, underneath Hawthorne Harbor which is located in the Harbor District in the western area of the town. The cave itself can be divided in two sections: the top section, and the bottom section. The bottom section accounts for three quarters of the volume of the cave and is filled with water. The top section accounts for a quarter of the volume and is filled with damp, breathable air, with a small island floating at the surface of the water of the bottom section.
The majority of this district serves as a residential area, but a few shops and inns have been built there as well. The buildings of the district are mostly made of more exotic material like coral, or other water resistant material. Most houses of this district are built in the bottom section, underwater, whereas the shops and inns are located on the island of the top section, outside the water. Only those that can breathe underwater and are comfortable underwater can live in the underwater portion of the district.
At the bottom of the cave, on the south-eastern side, a portal leading to the Elemental Plane of Water can be found. The portal to the Elemental Plane of Water is now guarded and secured for all Hawthorne Guild members to go through for adventures. The Sultan himself also gives missions to Hawthorne Adventurers whenever he needs something done via two of his emissaries that occasionally travel to and from Sultan Rezzo’s palace through the portal. These emissaries are Aukai, the Wanderer, a sea elf, and Brooke, the Swift, a water genasi.
The Inner Planes surround the Material Plane, the Shadowfell and the Feywild. They provide the substance from which the world was made. They are also known as the Elemental Planes. One of these planes is the Plane of Water, an endless sea with a warm sun across the sky and a plane in which the weather varies extremely. Throughout this plane are scattered gigantic coral reefs stretching out underneath the sea and above it, forming various islands. For more information on the Elemental Plane of Water, please refer to the Dungeon Master’s Guide, pp. 56 - 57.
DMs looking to run adventures in the Elemental Plane of Water are advised to refer to its corresponding section in the Dungeon Master’s Guide, pp. 56 - 57, as well as to refer to the rules for swimming and underwater adventuring and combat present in the Player’s Handbook and in the Dungeon Master’s Guide. Additional related rules regarding the use of ships and adventuring in nautical environments can be found in Ghosts of Saltmarsh, pp. 186 - 228. In addition to these official resources, DMs can also, at their discretion, utilize the following optional mechanics and rules below to reflect the challenges faced in adventures occurring in the Elemental Plane of Water.
Spells which create, affect, or utilize water in some way (as determined by the DM) are enhanced when cast within the Elemental Plane of Water. Such spells when cast are treated as if they were cast at one spell slot level higher and their normal duration is doubled, to a maximum duration of 24 hours. For example, an ice storm spell cast using a 4th-level spell slot in the Elemental Plane of Water is treated as if it had been cast at 5th-level, and a control water spell cast in the Elemental Plane of Water has a duration of 20 minutes.
Spells which deal fire damage or that create, affect, or utilize fire in some way (as determined by the DM) are more difficult to successfully cast within the Elemental Plane of Water. A creature attempting to cast such spells must make a DC 10 ability check using their spellcasting ability when casting the spell in order to successfully cast it. On a failed check, the spell fails and has no effect, and the attempt is wasted. This impedance does not apply to spells cast from magic items.
A variety of powerful currents run across the Elemental Plane of Water. DMs can utilize the rules for currents as described in Ghosts of Saltmarsh, pg. 203 for the purposes of incorporating currents and their mechanics in an adventure. Certain currents within the Elemental Plane of Water are particularly dangerous, capable of forming whirlpools or tidal bores. DMs can utilize the rules for whirlpools as described in Ghosts of Saltmarsh, pp. 206 - 207 or as per the control water spell for purposes of incorporating whirlpools and their mechanics in an adventure.
Tidal bores are massive currents that sweep across the Elemental Plane of Water, sowing destruction in their wake. DMs can utilize the rules for the tsunami spell, additionally affecting and damaging ships and nonmagical objects that aren’t worn or carried, for purposes of incorporating tidal bores and their mechanics in an adventure.
The majority of the Elemental Plane of Water is neither particularly cold nor warm across the surface of its endless sea. However, certain regions of the Elemental Plane of Water can form what are known as “hot spots” or “ice pockets.”
Hot spots are areas of water whose temperature exceeds 100 degrees Fahrenheit, creating areas of extreme heat (see “Weather” in chapter 5 of the Dungeon Master’s Guide). Certain hot spots are extraordinarily hot, often containing vortices linked to the Elemental Plane of Fire. Creatures submerged in the regions of such hot spots must make a DC 15 Constitution saving throw for each minute spent in such areas, taking 11 (2d10) fire damage on a failed save, or half as much damage on a successful one.
Ice pockets are areas of water whose temperature falls below 0 degrees Fahrenheit, creating areas of frigid water (see “Wilderness Hazards” in chapter 5 of the Dungeon Master’s Guide). Certain ice pockets are exceptionally cold, containing areas of solid ice and potentially connections to the Plane of Ice. Creatures submerged in the regions of such ice pockets must make a DC 15 Constitution saving throw for each minute spent in such areas, taking 11 (2d10) cold damage on a failed save, or half as much damage on a successful one.
Hot spots and ice pockets range in size, typically anywhere from 300 feet to 1 mile across. While such hazardous regions are usually difficult to perceive via sight, temperature often gradually changes when approaching the boundary of a hot spot or ice pocket. Creatures with a passive Perception of 10 or higher can usually determine they are approaching a hot spot or ice pocket and can attempt to maneuver around the area.
Contrary to its name, burn water isn’t actually hot, but is instead acidic in nature. Burn water consists of rare regions within the Elemental Plane of Water where portions of the Plane of Ooze form elemental pockets within the Elemental Plane of Water. Burn water is more commonly encountered by the Silt Flats which lie on the border between the Plane of Water and the Plane of Ooze, but can also be found in other portions of the Plane of Water. Such regions can range anywhere from a few yards to thousands of miles in size.
A creature caught in an area of burn water must make a DC 15 Constitution saving throw for each minute it spends in the area, taking 5 (1d10) acid damage on a failed save, or half as much damage on a successful one. A nonmagical object that isn’t being worn or carried also takes the damage if it is in the area.
Red tides are rare but dangerous patches of infected water. A creature caught in an area of red tide must make a DC 15 Constitution saving throw each minute it spends in the area. On a failed save, the creature suffers from the effects of the blinding sickness disease (as per the contagion spell) for the next 7 days: pain grips the creature’s mind as its eyes turn milky white, and the creature has disadvantage on Wisdom checks and Wisdom saving throws and is blinded.
As blinding sickness is a natural disease, any effect that removes a disease or otherwise ameliorates a disease’s effects apply to the target.
Sultan Rezzo is a noble marid (see Sultan Rezzo’s Statblock ) who reigns in a magnificent palace in the Elemental Plane of Water. He occasionally gives quests to Hawthorne Guild members. As long as the Hawthorne Guild remains in good standing with the Sultan, the guild will have freedom of access to the portal leading to an area near his palace in the Elemental Plane of Water. Sultan Rezzo is a kind and benevolent Marid as long as he is given the respect he considers himself to deserve. Otherwise, his fury can be as violent as the ocean when a storm causes waves to crash and sink ships and anyone inside it. He is the benevolent ruler of his palace, he gives his slaves many liberties and treats them fairly well. He is more interested in having slaves for the sake of ownership than actually making them do anything they wouldn’t want to. However, it seems pretty clear that his slaves are quite happy with their lives and are staying in the palace of their own will. Among those slaves, his two favorites are Brooke the Swift, a water genasi, and Aukai the Wanderer, a sea elf. They often serve as his messengers and emissaries.
Sultan Rezzo’s palace is a grandiose building covered in coral and algae. It is filled with wonders and sensory delights that goes beyond one’s wildest dreams. This opulent palace floats in a deep part of the Plane of Water and contains many luxurious chambers and rooms filled with air for his guests or slaves.
Rezzo is a Marid who sees himself as a superior being and expects to be treated as such. He wears fine and colorful clothes that resemble outfits usually seen in the Calimshan region.
Rezzo has a great sense of self-importance, and considers himself, as well as other Marids, above all other kinds of genies. He tolerates djinn, dislikes dao, and despises efreet. Bribery and flattery are the best means for a humanoid to earn Rezzo’s favor. In an adventuring group, whoever praises him the most will be seen by Rezzo as the most intelligent or worthy of the group and assume they are the leader. Rezzo loves to tell stories about himself or legends he knows, and although he will not directly lie about the events he recounts, he will greatly embellish them. He hates being interrupted while telling his stories, and will only offer a single warning before unleashing his wrath should this great offense be done to him.
Personality Trait. There’s nothing I like more than finding a new skillful slave. Ideal. Noble Obligation. It is my duty to protect and care for the people beneath me. (Good) Bond. I will do anything to prove myself superior to other genies. Flaw. Flattery brings down my defenses and I tend to be less cautious of those who compliment me. Quirk. I will always invite the one I deem most worthy in an adventuring group to join my kingdom as a slave.
If a DM wishes to add an extra minor property to one of the items obtained in the Elemental Plane of Water, or have their origins in the Elemental Plane of Water, it is possible to select a property from the list. The items must follow the guidelines for minor properties in the Hawthorne DM Guidelines.
| d10 | Minor Property |
|---|---|
| 1 | Aqua Affinity. While holding this item you can hold your breath for twice as long while underwater. |
| 2 | Aqua Sight. The wielder of this item can see normally in clear water, following the rules for visibility outdoors. |
| 3 | Steamy. While holding this item underwater, the water around the bearer appears to be boiling. While holding this item while not underwater, vapor seems to rise around the bearer, as if steaming. However, this item doesn’t modify the temperature of the environment. |
| 4 | Bioluminescent. The item is riddled with bioluminescent organisms that can shed a dim blue light. The bearer can use a bonus action to cause the organisms to shed dim blue light in a 15-foot radius, or to extinguish the light. |
| 5 | Sailor Compass. The wielder can use an action to learn which way is the nearest solid land. |
| 6 | Moist. This item is always wet to the touch. |
| 7 | Salty Air. While holding this item, the bearer always smells like the sea. |
| 8 | Lure. While holding this item underwater, small fish are attracted to the bearer. |
| 9 | Deep Diver. The wielder of this item can spend twice as long as normal swimming underwater at depths greater than 100 feet below the surface. |
| 10 | Bubbly. While holding this item, a constant stream of small bubbles emerge from the bearer’s body. Each bubble pops after a few seconds and has no other effect. |
For DMs wanting to learn more about the Inner Planes and the Elemental Plane of Water, we recommend reading the following material for inspiration.
This document has been created by Kathy in collaboration with Luolang and the Lore Consultants of the Hawthorne Dungeons & Dragons Guild.
Hawthorne Guild