Well this is an interesting collection of homebrew. I run a lot of D&D games with pirates, or boats, or underwater scenarios and was looking for a prestige class for an upcoming NPC in my 3.5 game. A were-orca barbarian who I wanted to have some water themed powers thrown in the mix. I figured there had to be something, and even if it wasn’t optimal, it could be cool. After some searching through my books, it turns out the answer is a big goose egg. There’s stuff for sailors, pirates, and even ocean based casters, but nothing for the martial guys. A glance told me the same was true for 5e. So todays entry is a mix of 3e and 5e homebrew to give some aquatic non-casters some love.

Leviathan Hunter

A 5e path for Barbarians who wrestle Krakens.

Aquatic. At third level, your barbarian gains a swim speed equal to half their base land speed. If they have a swim speed from another source, their swim speed is equal to their land speed or their original speed, whichever is higher. Additionally, you can breathe water if needed.

The Depths Below. From third level onward, while raging, you do not succumb to the pressure of the icy depths. You gain resistance to cold and bludgeoning damage, and darkvision.

Hang on For Your Life: Starting at 6th level, while raging, if you strike a creature whose size is larger than you, with a melee attack, you can make a free grab attempt. If you have it grabbed at the start of the creature’s turn, you can make opposed strength checks. If you win, you can pick its movement for the turn. If you fail, it can move normally. (you might enjoy some additional grab rules)

Squeeze: At tenth level, If you start your turn grabbing a creature, they take damage Xd6 bludgeoning damage where X is equal to your proficiency modifier. 

Tame the Beast: From 14th level on, if your Squeeze ability would slay a creature, you can instead choose to Tame it. A Tamed creature regards you as a friend and ally, provided you stop attacking it and treat it well. It will serve willingly as a mount until it takes its next long rest. This ability has no effect on creatures with language, culture, or civilization. 

Neptune’s Trident

A badass trident for 5e’s ocean warriors. 

This legendary trident provides a +1 to attack and damage rolls. When attuned, it always returns to the wielder’s hand in time for their next attack. When thrown, this trident deals 6d6 lightning damage, instead of the normal damage for a weapon of its size. 

Lastly, the trident has 7 charges. If attuned and wielding the trident, you can use an action and expend 1 charge to cast dominate beast (save DC 17) from it on a beast or monstrosity that has an innate swimming speed that you can see. Alternatively, you can expend 3 charges to change form to that of a Storm Giant with a mermaid’s tail and a 20ft land speed. While in storm giant’s form, your armor grows and stretches, and you retain your normal AC. You do not gain its actions or innate spellcasting. Instead, you can continue to throw your trident, or use it in melee, where it now deals 8d6 lightning damage, has 10ft reach, and can be used for two attacks per round. The trident regains 1d8 expended charges daily at dawn.

Ocean Master

A 3e path for warriors who have harnessed the oceans power.

• HD: D10
• BAB: Good
• Saves: Good Fortitude and Will
• Skills: 2 +Int
• Class Skills: Handle Animal (Cha), Intimidate (Cha), Jump (Str), Ride (Dex), Survival (Wis), and Swim (Str).
• New Proficiencies: None

Level 1 – Aquatic Affinity: You gain a swim speed equal to your base land speed, the amphibious ability, Darkvision 120ft, and a special resistance to pressure from oceanic depths. You do not take cold damage, bludgeoning damage, or any other ill effects due to oceanic depths. Lastly, you suffer no armor check penalty for light armor or shields when using the swim skill, and only a normal penalty (not double) with heavy armor.

Level 1 – Shape of Water: You can manipulate water touched. You can move, shape, or otherwise control up to 1 Gallon per HD of water as a standard action. This can be used for fun shapes and displays, or for two more practical effects. You must have a gallon of water available for either ability, and water blasted at a foe is obviously no longer within reach. 

1. Blast: As a standard action, you can blast a jet of water as a ranged touch attack at Close range. This jet deals 1d6 bludgeoning damage per 2 HD you possess. 
2. Shield: As an immediate action, you can call forth a shield of water to intercept ranged attacks. You gain +2 to your AC against a single attack, and a 20% miss chance due to concealment. 

Level 2 – Oceanic Bond: You gain the services of a loyal aquatic companion. This functions identical to the Druid’s Animal Companion feature, except it functions based on levels in Ocean Master. You can choose any Animal found in the Aquatic terrain (but not Any terrain), or a water elemental, so long as its CR is equal to your level -1. 

Level 2 – Underwater Friends: You can rebuke creatures (not just animals) with the aquatic subtype using your Ocean Master level as your Cleric level. You can use this ability 3 + Charisma modifier times per day.

Level 3 – Wall of Water: You can summon a wall of water as a Standard action. This functions as the Wind Wall spell with a caster level equal to your hit die. Instead of the Air descriptor, it should have Water. It summons a rushing flow of water from nothing, and functions identically in all other ways. While in effect, you can pull water from it to power your Shape of Water abilities as needed. You can only have a single Wall of Water active at a given time.

Level 4 – Shape of Water: You gain additional uses of your Shape of Water ability. 

1. Blast: Your Blasts range increases to Medium range.
2. Shield: Your Shield grants +4 AC and a 50% miss chance. 
3. Currents: As a standard action, you can shape underwater currents in a Line, 10ft wide and 10ft per HD long. Creatures (including yourself) move along the current at double their normal swim speed, and against the current at half. As you lay down Lines of Currents, you can have up to your Charisma modifier active at a given time. You can dismiss them as a standard action, or if you attempt to create more, the existing Currents are dismissed automatically starting with the oldest first. 

Level 5 – Echo Location: While submerged in water, you gain blindsight out to 120ft. 

Level 6 – From the Depths: You can add any creature with the Aquatic subtype to your list of options for your Oceanic Bond, provided their CR is equal to your level -2, or -4 if their Intelligence Score is over 8 or they have class levels.

Level 7 – Monsoons: By spending an hour, you can summon Hurricane-Force Wind to buffet a one mile radius centered on you. If you are in an ocean, or large enough lake, you can summon these winds with 10 minutes of focus. If you are free floating in the ocean, or on a ship without significant land within the one mile radius, you can summon these winds with 1d6 rounds of uninterrupted focus.