You will receive new objectives very soon. As a result, you will have to head on to the second ship (#1). Use the glowing area to reach the deck of that ship. Thankfully, you won't have to destroy any crates here, so focus only on attacking the monsters (#2). Just as before, it would be a good idea to try and score a combo sequence here.
You will have to keep hitting the monsters for about a minute. Once this is done, a new cut-scene is going to be displayed on your screen (#1). You'll going to be playing as Will Turner. This is going to be the first part of the boss fight. Thankfully, it's quite simple. I'm sure that you won't have any problems hitting the boss (#2). Go ahead and perform several stronger attacks.
You will be taking part in action sequences from time to time (#1). You should be familiar with these types of actions, however you must press certain attack keys faster than usual. You will also have to press movement keys during one of the sequences. Once you've finished the first part of the fight, a short cut-scene is going to be displayed on your screen (#2). As you've probably suspected, you will be playing as Jack Sparrow from now on.
You shouldn't change anything in your approach (#1). Focus mostly on faster attacks, because they'll be most successful, however you may also consider choosing more powerful strikes from time to time. You should also notice two interactive ropes (#2). Cutting them down will allow you to apply additional injuries to the boss. You will have to press the action key while standing next to the rope in order to activate such an action.
Get ready. You will have to participate in your final Jackanism mini-game (#1). I guess I won't have to warn you by saying that it's going to be quite difficult (especially near the sixth action). If you've successfully completed previous Jackanism mini-games, you should also be able to win this one. The final phase of the battle is going to be very simple (#2). Choose faster attacks. You will also have to block some of the counter-attacks performed by the boss.
Once you've defeated the boss, you will have to watch two separate cut-scenes. The second cut-scene is going to be more important (#1). You will have to defeat Beckett and his men. This is going to be your final task for this mission. Start off by attacking Beckett's mercenaries (#2). This is a great opportunity to score a much needed combo sequence, however you must be in a lot of hurry.
You will also be able to pick up two final crab pendants. You must visit two opposite sides of the ship (#1; #2). Check both screens if you want to find out where to look for the pendants. As a result, you will be able to take third and fourth pendant. You should have already fulfilled all of the available side missions, so you'll be able to focus on the main task at hand.
Let's proceed with the final part of this level. If you don't want to lose too much time or health then I recommend that you follow my instructions. Once again, you will witness a short animation that's going to be a warning (#1). The cannons are about to fire, so you'll have to find a cover. I would recommend hiding behind large groups of crates (#2). You should be able to find at least two of these spots on the main deck of this ship.