Diverman

The Diverman is an NPC vendor that will spawn once the following conditions have been met:


 * There is an empty house.
 * The Queen Jellyfish has been defeated.

When threatened by enemies, he will defend himself with a harpoon gun.

Air Tank
Upon clicking on the "Air Tank" dialogue option, if you do not already have one in your inventory, the Diverman will provide you with an Emergency Air Tank, free of charge. This special item will automatically restore your breath meter back to full should it reach critical levels, but in the process will become empty. The player can then return the empty tank to the Diverman and refill it by clicking on the same option.

Names
The Diverman can have any of the following names: 
 * Adin
 * Alexander
 * Austin
 * Calder
 * Cameron
 * Elijah
 * Ethan
 * Francis
 * Maxwell
 * Neil
 * Nolen
 * Percy
 * Robert
 * Sam
 * Stephen
 * Zane

Interaction quotes

 * "Have you adventured into the aquatic depths yet...? Its choking atmosphere prevents most explorers from entering, but I'm confident you'll find a way around it..."
 * "I've collected many marine items in my travels, hero. Would you like to purchase one?"
 * "Being at the bottom of the ocean for long periods of time has taught me one thing. Always come prepared!"
 * "You ever try to drink a bottle of water, while drowning, to save yourself? I know I have!"

When homeless:
 * "Visiting that sea rift again wasn't my best idea... that mutant jellyfish almost ate me whole!"
 * "Yuck... that vile creature almost got away with eating me! Thank you for saving me, hero."

When Angler is present:
 * "That little twerp, , thinks he knows so much about the sea..."

When Pirate is present:
 * "You wouldn't believe it, but  and me go way back. He wasn't always a salt water scourge, yunno'."

When the player clicks Air Tank:
 * If the player does not already have an Emergency Air Tank (gives an Emergency Air Tank):
 * "Here you go friend! This air tank will automatically activate when your breath reaches critical level. Come visit me afterwards and I'll refill it free of charge!"


 * When the player already has an Emergency Air Tank:
 * "Hmm, your air tank looks full to me... Did you just want to chat? I have all manner of tales to tell!"


 * When the player has an Empty Air Tank:
 * "Let me refill that air tank for you, friend. Do continue to take caution out there; Terraria needs you alive and well..."

Trivia

 * The name "Sam", in conjunction with the Diverman's occupation, is a reference to the creator of the Thorium Mod, DivermanSam.
 * The Thorium Cube that he drops is also a reference to him.
 * The line "Have you adventured into the aquatic depths yet...? Its choking atmosphere prevents most explorers from entering, but I'm confident you'll find a way around it..." directly references the Aquatic Depths biome and the Choking Aura debuff.
 * The Diverman has the highest defense of any town NPC in the game.