Union Bosses can be found in the Pirate Union section and can only be opened by Union Captain or First Mate. There is a 24 hour time frame for union mates to choose their trophy, and 48 hour cool down on each boss. Trophies are awarded on a 1st come basis, so you may have to wait if the number of applied exceeds the number available (better to choose a different trophy that's available and then reapply early in the next 24 hour time frame).
Trophies are awarded at 20:00(Ingametime GMT+7).
You can apply for your next trophy. You can only choose 1 trophy in total, NOT one for each boss.
For each Fight you get at least 50 Pirate Coins (Even if you don't land a single hit)
For each 1k dmg you deal to the boss you gain 1 additional point - means at a total of 950k dealt dmg you will get 1000 Pirate Coins as reward.
The First Boss has a total HP of about 10.000.000 - means each fight will take at least 10% of their life, if you gain 1k Pirate Coins
The Second Boss has a total HP of about 20.000.000 - means each fight will take at least 5% of their life, if you gain 1k Pirate Coins
The Third Boss has a total HP of about 30.000.000 - means each fight will take at least 3,3% of their life, if you gain 1k Pirate Coins
The Fourth Boss has a total HP of about 40.000.000 - means each fight will take at least 2,5% of their life, if you gain 1k Pirate Coins
~ These Values are approximated based on some tests, further testing is necessary to clarify the exact Values.