I've been trying to unlock this for about 3 hours. after reading the requirement, I'm boarding, and killing the enemy crew and doing the random second requirements, but I'm not receiving credit. At least I think I'm doing it right. I sunk one which only had about 5000 or less but I'm wondering if it is just me, or am I doing something wrong? going for ship markers /_|R.
I just really want this figurehead. In my mind I'll play the game out like parts of the Jackdaw are hand-me-downs from Grampa Kenway for Connor :)
'Get a reputation for answering phones, and all they do is ring.' - Luther
Okay, so I've plundered plenty of royal convoys. The blue ones. That you can (and I did) share online. Plundered all of the ships in the convoy (I think the only "official" or constant ones are a frigate and two schooners - it seems like the other ships are randoms and/or go away, but the convoys ALWAYS have those three). Did three in one playthrough. Nothing.
I think they have to be ones that you did not discover and share (i.e., plunder 3 royal convoys shared by your friends).