What did odysseus' crew do to him when they neared the island of the sirens?

At dawn Circe left and Odysseus prepared his men for departure. He addressed them warning them that there was danger ahead. He told them about the Sirens but purposefully left out Scylla and Charybdis. When they neared the island of the Sirens, the men put in their ear plugs and lashed Odysseus to the mast. As the song got louder he thrashed more and more but they just tied his bonds tighter.

That's what his crew did.