Does alonso know that his son is alive in the tempest?

In Shakespeare's "The Tempest," Alonso does not initially know that his son, Ferdinand, is alive. Throughout much of the play, he believes Ferdinand has drowned in the shipwreck caused by Prospero's magic. It is only later, when Ferdinand is revealed to be alive and reunited with Alonso, that he discovers the truth. This revelation plays a significant role in the themes of reconciliation and redemption in the play.