I have been researching this port as well for a September trip on HAL. I'm currently on the waitlist for the Lagoon tour. As a backup plan I found the same tour you are asking about through Viator. When I clicked the link to reserve, I received a disclaimer saying the tour is with a private individual and may not be protected under the same consumer protection rules under EU and UK law. I have used Viator numerous times in numerous countries and have never received this disclaimer. I'm a little hesitant to proceed.