Pirate

Pirates are daring and cunning rogues who have made a name for themselves on the high seas as ruthless warriors. They are quick on their feet, skilled in combat, and always looking for their next big score. Whether they are pillaging ships, hunting for treasure, or just causing mayhem, pirates are never to be underestimated.

Taken and reworked from Torrents of the Spellhoarder by Elderbrain.com.

Level 3: Sea Legs

Level 3 Pirate feature

You become an expert in navigating a ship and swimming in water. You gain a Climbing Speed and Swimming speed equal to your Walking Speed. 

You have advantage on saving throws against being knocked prone.

Level 3: Sea Dog

Level 3 Pirate feature

You gain a deep understanding of ships and sailing, giving you proficiency with water vehicles and advantage on all Intelligence (Nature) checks related to the sea and maritime knowledge.

Level 9: Plunderer's Trove

Level 9 Pirate Feature

You become an expert in plundering ships and coastal towns. You can always determine if a chest or door is trapped, and you have advantage on Dexterity (Sleight of Hand) or Dexterity (Thieve's Tools) checks made to open locks.

Level 9: Part of the Ship

Level 9 Pirate feature

You're not a landlubber. You fight better on your own ship than on sturdy ground. You have advantage on all Attack Rolls made while you are on a vessel that is owned by you or by your party.

Level 13: Finesse Weapon Master

Level 13 Pirate feature

You have mastered the art of fighting with a finesse weapon. When you roll damage for a weapon attack with a finesse weapon, you can roll an extra damage die.

Level 17: Dread Pirate

Level 17 Pirate feature

You become an expert in frightening your enemies. Whenever you score a critical hit or reduce a creature to 0 hit points, creatures of your choice within 30 feet of you who can see you must make a Wisdom saving throw (DC equals 8 + your Proficiency Bonus + your Charisma modifier) or become frightened of you for 1 minute. They may repeat the saving throw at the end of their turn, ending the Frightened condition on themselves on a success.