Throughout the play testing of this game we all have heard and asked about incentive to play and game progress. Honestly I am all for horizontal (cosmetic driven) progress as it doesn't provide an advantage to early adopters or disadvantage to "less" skilled players or those picking up the game a year+ later.
That said the cosmetics available have to feel rewarding and compel players to continue playing and various clothing and weapon skins aren't really enough. I think once a player reaches the end game (becomes a pirate legend) there should be purchasable items like ships, spawn islands, pets, games, and cosmetic items that provide an altered (no pvp buff) game-play experience.
For example there could be an amulet of drunkenness, compasses that provide track/display step count. telescopes that assist with finding treasure or spotting ships (spotting is questionable) etc. How do you think cosmetics could be improved to provide player incentive?