Here is the full list of all 39 Sailing Era achievements.
Obtain all the trophies
Complete Abdullah's Main Quest: Chapter 4
Complete Abdullah's Main Quest: Chapter 3
Complete Abdullah's Main Quest: Chapter 2
Complete Abdullah's Main Quest: Chapter 1
Complete Yoshitaka Shizuma's Main Quest: Chapter 4
Complete Yoshitaka Shizuma's Main Quest: Chapter 2
Complete Yoshitaka Shizuma's Main Quest: Chapter 3
Complete Yoshitaka Shizuma's Main Quest: Chapter 1
Complete Andrew's Main Quest: Chapter 4
Complete Andrew's Main Quest: Chapter 3
Complete Andrew's Main Quest: Chapter 2
Complete Andrew's Main Quest: Chapter 1
Bring down 1 enemy ship with naval mines
Bring down 1 enemy ship with a ram
Obtain every unique equipment
Discover all the fisheries
Bring down 1 enemy ship with a single round of shooting
Reach Max Favorability with bar girls at all the taverns
Reach Level 99 with 1 character
Sail for 100 days in a row
Discover all the ports
Salvage 10 shipwrecks
Discover all the waters
Earn 1,000,000 in profit from a single transaction
Complete Yun Mu's Main Quest: Chapter 4
Complete Yun Mu's Main Quest: Chapter 3
Complete 10 bounty quests
Unlock 40 routes
Unearth 10 treasures
Reach Max Contribution at 1 port
Complete Yun Mu's Main Quest: Chapter 2
Force all the enemy ships into surrender in a battle
Establish 3 commerce guilds
Gain a flawless victory in a Hand-to-Hand Combat
Fulfill 10 business contracts
Win a battle by bringing down the flagship of a fleet
Complete Yun Mu's Main Quest: Chapter 1
Explore for 100 days in a row