What should he do?
The dilemma forced upon him was one of those which Katharine had foreseen, and of which they had talked together.

He, apparently, must decide between his love and his country.

If he held on when he reached the mouth of the channel and passed it by, the capture of the ship was absolutely inevitable.

If he went through the channel and enticed the English ship after him, the death of his sweetheart was likewise apparently inevitable.
Chasing with the determination shown by the English captain, who had his topgallantsails still set, and with the little warning he would have of the existence of the shoal, owing to the rapid closing of the day, the frigate would have to attempt the channel, and in that way for that ship lay destruction.
Save Katharine-- Lose the ship.

Save the ship-- Lose Katharine.
Love or Duty--which should it be?
The man was attacked in the two most powerful sources of human action.