Pirates of the Caribbean: Dead Man's Chest Notes

Plausible
There may have been sword fights
There would be pirates around that time
Parents are hunted by the british navy
Some captains/leutenients may have been demoted if they aid a pirate
Some evil government official might use that for his own facinations

Impossible
There can't be people walking around with octopus's heads
A ship can't sink under the ocean and still come back up
The Kraken is not real
People can't have heads of octopuses and walk around under the ocean
There is no compass that points to your heart's desire