East India Trading Co ship?
 

east india ships are the white/black flagged ships with the EITC before their names.

for example, the viper, is an eitc ship.

yes and does it says sink an EITC frigate or Galleon? bc if it does u must sink a frigate or galleon fromt he EITC

Many people get frustrated with this task thinking they need to actually board the EITC ship to capture the flag. But really you just need to sink one.

I don't remember if this task is one where you can sink any EITC ship, such as the sea viper. Or if you have to sink a galleon or frigate, corvette or sentinal.

I'm pretty sure it's just any EITC ship, I was always relatively low in sailing when I got that task and I don't remember going after anything higher than a viper when I got it done.

When the game tells you to sink a frig or galleon, you can also sink the light or war varieties and have it count.

Now if there's a level dependancy its another story.