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