The College Of Sirens

While most bards master their art on dry land, some discover their talents while at sea. Known as Sirens, these bards are more comfortable on the deck of a boat than the stage in a tavern and are quick to motivate their friends with a rousing sea shanty or sap their foes with dreadful dirges of despair. Combining their knack for vocal magic and their intimate connection with the high seas, Sirens conjure the spirits of drowned sailors to fight alongside their crew one last time.

Sea Legs

When you join this College at 3rd level, you gain a climbing speed and swimming speed equal to your movement speed, and you can hold your breath underwater for a number of minutes equal to 10 + your Constitution modifier

Song Of the Sea

 Also starting at 3rd level, you can use your song to call forth the spirits of those who have drowned at sea. At the end of a long rest, you can perform a mournful song that summons a Drowned Phantom. When you do so, you choose to summon the spirit of a Cook, Gunner, or Oarsman, which determines its abilities. The Drowned Phantom is friendly to you, obeys your commands, and uses the Drowned Phantom stat block, which uses your proficiency bonus (PB) in several places. In combat, the Phantom acts during your turn. It can move and use its reaction on its own, but the only action it takes is the Dodge action unless you use a bonus action on your turn to command it to take one of the actions from its stat block, or another action. If you are incapacitated, it can take any action it chooses, often choosing to protect you. If your Phantom was destroyed within the last hour, you can expend a spell slot of 1st-level or higher. After 1 minute, it returns from beyond the veil with its hit points restored.

Siren's Curse

Your mournful songs of the sea can mark your foes for death. Beginning at 6th level, when you use Countercharm, you can mark one enemy creature within its range for death. While your Countercharm is active, your Phantom has advantage on its attack rolls against the marked creature, and the marked creature has disadvantage on any saving throw your Phantom forces it to make.

Ghastly Wail

You can banish your Drowned Phantoms back to their watery graves with a horrible screech. Starting at 14th level, you can use a bonus action to banish your Phantom back to its grave, completely destroying it in the process. As it dies, it lets out a horrifying wail, forcing creatures of your choice that can hear the Phantom within 30 feet to make a Wisdom saving throw. Creatures take 6d8 thunder damage on failed save, and half as much thunder damage on a successful save.