Sea Elf (5e Subrace)
From D&D Wiki
Sea elves are an aquatic subrace of elves that rely on water, and only live near water.
Ability Score Increase. Your Constitution score increases by 1.
Amphibious. You can breathe air and water.
Natural Swimmer. You have a base swimming speed of 30 feet.
Aquatic Weapon Training. You have proficiency with javelins, nets, spears, and tridents.
Extra Language. You can speak, read, and write Aquan.