Here is the full list of all 16 Pirates: Golden tits: Chapter 1 achievements.
Journey Begins
Win an armwrestling tournament 5 times
Spend 20000 escudo
Finish 10 bounty hunting commissions
Activate a cheat mode
Have a total of 10000 Escudo on yourself
Catch 50 fish
Fully upgrade your ship
Spend 100 days sailing
Touch Jaina while she's asleep
Peek at the bathroom
Sink 10 ships
Leave an uninhabited
Beat Saint-Isidor bandits 5 times
Visit a brothel 10 times
Listen to all of the Twig's poems