Mariner

You have undergone extensive training on a ship and at sea, you gain the following benefits:

• Increase one ability score of your choice by 1, to a maximum of 20.
• You gain proficiency in Navigator's tools and Vehicle's (Water).
• You gain expertise with Navigator's tools and Vehicle's (Water), which means your proficiency bonus is doubled for any ability check you make with it. This has no effect if you are already doubling your proficiency bonus from another effect.
• As long as you are not wearing heavy armor or using a shield, swimming does not cost you extra movement, and you gain a +1 bonus to AC while underwater.