Water Spells
Here are some additional spells all featuring oceanic elements as possible options for aquamancers.
Bubble
Conjuration Cantrip (Bard, Druid, Wizard)
Casting Time: Action
Range: 30 feet
Components: S
Duration: Instantaneous
An air bubble forms around an appendage of a creature you can see within range. It contains breathable air and lasts until the end of your next turn. If the creature takes damage, the bubble pops, forcing the creature to succeed a Constitution saving throw or take 1d12 Thunder damage.
Cantrip Upgrade. The damage increases by 1d12 when you reach levels 5 (2d12), 11 (3d12), and 17 (4d12).
Geyser
Level 1 Evocation (Druid, Sorcerer, Wizard)
Casting Time: Action
Range: 60 feet
Components: V, S, M (a rock from a hot spring)
Duration: 1 minute
You cause the ground to erupt into a sudden scalding geyser in a 10-foot square on a surface that you can see within range. The geyser acts as Difficult Terrain for the duration.
When it appears, each creature within the area must make a Dexterity saving throw, taking 1d8 Fire damage and 1d8 Bludgeoning damage on failure, or half as much on a success. This damage ignores Resistance to Fire damage granted due to being underwater.
Using a Higher-Level Spell Slot. The Fire damage increases by 1d8 for each spell slot level above 1.
Soak
Level 2 Transmutation (Druid, Sorcerer, Wizard)
Casting Time: Bonus Action
Range: 30 feet
Components: V, S, M (a glass ball filled with water)
Duration: 1 minute
You soak the target in mystic water. The target gains Resistance to Fire damage for the duration. In addition, the first time the target takes Lightning or Cold damage they take an additional 3d8 damage of the same type and the spell ends. An affected creature may take an Action to attempt to scrape the water off of itself, making a Strength saving throw. On a success, the spell ends.
Using a Higher-Level Spell Slot. The damage increases by 1d8 for each spell slot level above 2.
Cold Plunge
Level 3 Enchantment (Druid, Wizard)
Casting Time: Action
Range: 90 feet
Components: V, S
Duration: Concentration, up to 1 minute
You reach out to a creature you can see within range. For the duration, a freezing sheet of water envelops them, forcing them to succeed a Strength saving throw at the start of each of its turns or take 2d4 Bludgeoning damage and become Restrained until the start of it’s next turn.
When this spell ends the water violently condenses and freezes. The target must make a Constitution saving throw. On a failure they take 2d10 Cold damage, taking half as much if successful.
If the target takes Cold damage whilst Restrained by this spell, the spell ends immediately and the Cold damage this spell deals is increased to 4d10.
Using a Higher-Level Spell Slot. The Cold damage increases by 1d10 for each spell slot level above 3.
Water Belt
Level 3 Evocation (Sorcerer, Wizard)
Casting Time: Action
Range: Self
Components: V, S, M (a pearl worth at least 1000+ GP)
Duration: Concentration, up to 1 minute
You create three streams of water which rapidly spin around you. When you cast this spell, or as a Magic Action on a subsequent turn, you can expend any number of rings and make that many Ranged spell attacks against a creature within 60 feet of you. On a hit, the target deals 2d8 Bludgeoning damage.
When a creature makes a melee weapon attack against you, you can use your Reaction to expend a ring and force them to make a Strength saving throw. On a failure, their attack automatically misses and the creature is pushed 15 feet directly away from you.
Using a Higher-Level Spell Slot. You create an additional ring for each spell slot level above 3.
Oisin’s Brilliant Deluge
Level 5 Conjuration (Cleric, Druid)
Casting Time: Action
Range: 120 feet
Components: V, S, M (a vial of holy water)
Duration: Concentration, up to 1 minute
You create a 30 foot radius, 120 foot tall column centred on a point within range. Purifying rain falls within the column’s space. When the column is created, you may choose any number of creatures within it’s area to gain 5d6 Hit Points. In addition, if any of the chosen creatures are subject to one of the following conditions: Blinded, Deafened, Paralysed, Stunned or Poisoned, you may end that condition.
The column persists for the duration, it’s area is Lightly Obscured, and creatures within it’s area have Resistance to Poison and Fire damage.
Conjure Frogdens
Level 5 Conjuration (Druid, Wizard)
Casting Time: Action
Range: 120 feet
Components: V, S, M (a stone figurine of a frog)
Duration: Concentration, up to 1 minute
For the duration you create up to five 5 foot diameter puddles on the ground at points you can see within range. Creatures of your choice may expend 5 feet of movement in order to teleport from a space within 5 foot of any puddle to an unoccupied space within 5 foot of any other puddle created by this spell.
River Snake
Level 6 Evocation (Sorcerer, Wizard)
Casting Time: Action
Range: 60 feet
Components: V, S
Duration: Concentration, up to 1 minute
You cause a watery snake to tear forward in a 5 foot wide, 60 foot long Line originating from you. Each creature in the Line must succeed a Strength saving throw or take 10d6 Bludgeoning damage, and be pushed 15 feet along the length of the Line, falling Prone. On a successful save a creature takes half the damage only.
As a Magic Action on a subsequent turn, you can cause the snake to charge again in a 5 foot wide, 60 foot long Line originating from the end of the last Line that you created with this spell.
Liquify
Level 7 Transmutation (Warlock, Sorcerer, Wizard)
Casting Time: Action
Range: 60 feet
Components: V, S, M (spinal fluid)
Duration: Until Dispelled
You fire a stream of colourless liquid at a target creature you can see within range.
The creature must make a Constitution saving throw. On a failed save, they take 14d10 Cold damage and start to liquidate, subtracting 3 from it’s Strength and Constitution scores. After every 24 hours they repeat this saving throw. On a success, the spell ends. On a failure, their Strength and Constitution are reduced again.
If this damage would reduce a creature, to 0 Hit Points, or if either their Strength or Constitution scores are reduced to 4 or below, the creature is converted to a pool of colourless liquid alongside all non-magical objects they it is wearing and carrying. The target can be revived only by a True Resurrection or a Wish spell.
Watery Grave
Level 9 Conjuration
Casting Time: Action
Range: 1 mile
Components: V, S, M (A pearl worth at least 10,000+ GP)
Duration: Concentration, up to 1 minute
You create a 120-foot radius sphere of swirling water centred on a point within range. Nonmagical terrain within the sphere is destroyed. Creatures that cannot breathe underwater run out of breath 4 times as quickly while within this Sphere.
Creatures that start their turn inside of the Sphere must make a Strength saving throw. On a failure they take 15d6 Bludgeoning damage, and their Speed is reduced to zero until the beginning of their next turn. Creatures with a Swim Speed make this saving throw with Advantage. On a success a creature takes half as much damage only.
The first time a creature within the Sphere takes Lightning damage each turn, every other creature within the Sphere takes half as much.