Plot hole: Ships only steer when moving 'through' the water, not while adrift (moving 'with' the water/current). So the whole idea of fixing the rudder to steer away from the rocks without any propulsion is nonsense.
Plot hole: The crew of the Antonia Graza is shown blowing off the door to where the gold is by putting an explosive on the INSIDE of the door. What was the purpose of blowing off a door AFTER going inside the door, planting the explosive, then going back out?
Plot hole: After the tugboat is sunk, the crew try to repair a very old ocean liner - the ghost ship - using equipment that could only have come from the tugboat, which had the latest scuba gear and welding gear, but they are all at the bottom of the ocean in the blown-up tugboat.