Nothing of the kind had ever before happened there.

Two ladies and a most respectable old gentleman sailing away under the skull and cross-bones! That was altogether new in the Caribbean Sea.

To those who talked to him about his quixotic expedition, Captain Ichabod swore--and at times, as many men knew, he was a great hand at being in earnest--that if he carried not his passengers through their troubles and to a place of safety, the Restless, and all on board of her, should mount to the skies in a thousand bits.

Although this alternative would not have been very comforting to said passengers if they had known of it, it came from Captain Ichabod's heart, and showed what sort of a man he was.
Old Captain Sorby came to the Restless in a boat, and having previously washed one hand, came on board and bade them all good-bye with great earnestness.
"You will catch him," said he to Kate, "and my advice to you is, when you get him, hang him.

That's the only way to keep him out of mischief.
But as you are his daughter, you may not like to string him up, so I say put irons on him.