Watery Magic Items

These are inspired by a Facebook post I responded to.  The poster asked for aquatic magic items, and these were some of my suggestions.

Shark-Tooth Necklace

This large black shark's tooth hangs from a stout silver cord, with several beads and smaller teeth to either side.  In addition to providing the wearer with a +1 bonus towards Charisma-based checks with sea folk and sailors and such, it also curses the wearer with becoming a wereshark.  Before the first change, the wearer develops a massive appetite, preferably for raw flesh.

While transformed, the wereshark becomes a temporary NPC and performs one of these actions (or something similar, but aquatic).  

Remove Curse at DC 12 allows the wearer to remove the necklace, but the DC increases by 1 for each sentient being slain.  Upon killing a full score of beings, the curse cannot be removed except by slaying the wereshark, whereupon slayers tend to claim the necklace as loot and the cycle begins anew.

Figuring of Wondrous Power: Driftwood Dolphin

When activated (it must be submerged in salt water and the command word Flipper is uttered), a full size playful and intelligent dolphin grows and splashes in the water, awaiting its command.   This dolphin will carry you to shore, scout out a location, fetch something underwater (or carry something under), and attack on your behalf.  

Should the dolphin die, it remembers you when it returns and is not amused.   Dead or dismissed, the dolphin shrinks back into the driftwood carving and may be carried away by the waves if the controller is not quick. 

In fact, this is how the statue changes hands - it is often found washed up on a beach.

Coral Helm

Amy Weber, Coral Helm, 1994

This pink coral helm was obviously grown, but its odd symmetry suggests guidance in its growth, perhaps from sea elves, perhaps from tritons, perhaps from a bored sea god.  Regardless of how it was formed, the Coral Helm is a wondrously useful tool for land dwellers.  Most importantly, it allows whomever dons it to breathe saltwater as if it were oxygen, and to see through the dim ocean waters as if it were normal lighting.  In addition, it allows the wearer to swim as if a sea elf and the ability to speak and summon sea life (although not control it, but the wearer doesn't know that).

The longer one wears the Coral Helm (either cumulatively or straight in a row), the more at home they become in the ocean, and the more they prefer to remain.  Webbing grows between the fingers and toes, gills open on the neck, and the wearer becomes incapable of breathing air.  After three months of use, the wearer feels an unavoidable urge to dive down to the ocean floor, where she curls up and becomes the seed of a new coral reef.  Regardless of how long submerged, the Coral Helm always remains at the top of the reef, easily harvested by those curious.  Digging into the roots of reef, directly below the Coral Helm may reveal the remains (or at least some of the magical and metal bits) of its last wearer. 

What effects potions carried have on the growth of the reef are uncertain, but makes for fascinating debates among half-drunk water wizards.

Conch of the Tritons

There are several versions of this Conch Horn.  

1. Basically a Horn of Valhalla (DMG p175), but only works underwater, and the warriors summoned are tritons, sea elves, or sahaugin, depending on the Conch's alignment.  

2. Formerly belonged to a Triton Princeling, and like all such horns, has a unique sound tied directly to that Princeling.  Tritons that respond will not be amused to find a non-Triton sounding the horn, but will not immediately attack.  They will demand to know how the PCs gained the Conch Horn and what became of the Princeling. 

3. Stormcalling.  When blown, a storm begins brewing around the caster (see the spell Control Weather), quickly spinning up into a hurricane.  Once sounded, the storm begins to brew, until the equivalent of a Cat 5 Hurricane strikes the land, centered upon wherever the horn was blown.  While the storm takes a day or two to hit full destructive potential, it blows itself out by the end of day three.  Note that the supernatural nature of the storms summoned make them excellent breeding grounds for lightning elementals.

4. Summoning.  Sounding this horn is dangerous, as one of the following hears, responds, and wants a damn good reason for why it was summoned.  If it doesn't like the reason, it attacks.  1: Kraken  2: Dragon Turtle  3: Leviathan  4: Sea Giant  5: Elemental Water Dragon   6:  Charybdis   Note that this Conch Horn is the real reason behind several coastal legends of apocalyptic city-sinkings and terrible storms.  Edit: Then again, the Conch Horn of Summoning might call up a whale, instead.

Lanyard of Flotation

Anything this lanyard is properly attached to floats, incapable of sinking entirely.  Heavier objects float along just under the surface, the ball of the lanyard remaining visible (and strangely dry) above the water.  As might be imagined, these Lanyards are actively sought and well-protected by pirates, marines, and others who spend too much time on the water.

Attaching a Lanyard of Flotation to a body does not prevent drowning nor even the body being eaten.  It merely keeps it afloat.  Rumor has it that bodies kept afloat too long become a terrible form of undead.

Edit: Wow! I stumbled across this d100 list at Elfmaids & Octopi, and it puts my work to shame.