Continuity mistake: The right side of Elizabeth's face is twice slapped very hard (first by Boswain and second by Barbossa) but she never has a noticeable bruise, swelling, or other injury to her jaw or cheek.
Continuity mistake: When the Pearl chases the Interceptor the sea changes frequently from rough, to (relatively) calm sea. That cannot change that rapidly.
Continuity mistake: Between the two shots of Pintel and Raggeti's cannon, the position of the cutlery around the porthole changes entirely.
Continuity mistake: During the Black Pearl's ambush on Port Royal, they destroy a wall to the prison. Pirates in one cell manage to escape from a hole in the wall destroyed by one of the boat's cannons and Jack is stuck in his cell because the hole isn't big enough for him to fit through. As this happens, we can actually see the small hole when one of the pirates say "My sympathies. You've no manner of luck at all" as the other pirates escape the cell. Yet in the next shot as Jack is watching the other pirates escape, the small hole in Jack's cell is now smaller than it was in the previous shot.
Continuity mistake: After young Elizabeth tells young Will "I'm watching over you", there's a strand of hair over his ear, which appears and disappears randomly depending on the shot.
Continuity mistake: Young Will lays unconscious by the edge of a blanket. When the angle changes there's much more blanket behind.
Continuity mistake: Barbossa's scar changes appearance several times during the movie. At times it's almost completely gone, and sometimes it's even quite "thick".
Chosen answer: Because they'd have to find it. The gold may "call to them", but it obviously doesn't function as a millimetre perfect homing beacon or they'd never have missed the medallion years earlier when they attacked the ship carrying the young Will. Elizabeth drops it into the sea and they're going to have to spend what could be months trying to locate it - currents could take it well away from the dropping point. They've found the final missing piece; they're potentially just hours away from finally being cured. The last thing they want is to see it thrown into the sea.
Tailkinker ★
Well, if the crew was anxious to get the medallion then why did they act like they weren't interested in it before Elizabeth pretended to drop it?
Reverse psychology.
Ssiscool ★
What do you mean by reverse psychology?
By showing they are not interested in the medallion they are hoping Elizabeth will just drop it on the floor or chuck it to them as it's of no real value. However when she releases a bit of chain and the medallion drops, and the pirates lurch forward revealing that they really want the medallion and as such Elizabeth now has the upper hand in negotiations.
Ssiscool ★
I'm guessing Elizabeth wasn't fooled when the pirates showed disinterest in the medallion.
That's not called reverse psychology, which is used to encourage someone to change his or her mind. Doesn't work with a threat. They are feigning indifference to hide the importance of the object.
lionhead
They didn't want to give her an advantage over them. Pretending to not care about the coin would make Elizabeth think that the coin is worthless and cannot use it to barter a deal.