As the boat is approaching the island, Bond and Severine are at the front of the boat, looking at the island. Severine says something like "there's still time to turn around" and Bond says something like "no, I don't think there is" -- and just then, the shot widens to show the ship's crew slowly approaching Bond and Severine with their guns drawn.

So **the crew took Bond and Severine prisoner just before reaching the island.**