Ghost Pirates of the Sea-erra Madre

You tell the merfolk that you're very honoured that they would like you to visit their home, but that you simply can't due to surface reasons.

You begin to leave, but realize that the merfolk have surrounded you and are all brandishing harpoons in a sinister way.

You shine your laser light at them and then push the sink button on your sub, setting off the sirens. This also sets off the sirens who were among the merfolk. Their rousing battle songs turn to a noise that makes you feel ill.

Your sub quickly descends to the sunken ship and you eject and swim inside. Hopefully this will allow you some time to think about what to do next.

Inside the ship you see a skeleton sitting at a desk. Upon seeing you the skeleton gets up and waves at you!

Getting over your initial fear (one friendly skeleton seems preferable to dozens of angry merfolk) you begin to talk with the skeleton.

You explain your situation and the skeleton advise that you push the giant technologically advanced button marked "do not push" that seems incredibly out of place inside this ancient sunken ship.

You could push the button or you could hide out and wait inside the ship.