The crossing is part of it
The island is not somewhere you can walk to on your own. Plan to arrive at Sluisplein well before your booked boat and allow for the full length of the programme.
First with the guide
The guided tour provides context on the fort and its parts. Time for exploring on your own afterwards is mentioned; follow the instructions about accessible areas and returning to the boat.
A day from the calendar
Public open days are spread across the season. A general mention of the month is not enough: the specific date and sailing determine whether a visit is possible.
Before you go
Check the departure, the return journey and any changes due to the weather. Discuss boarding and the route across the site in advance; a ticket does not mean that every part of the island is accessible to everyone.
Sources
This information has been compiled from public sources. Not everything has been confirmed by the museum itself; please check opening hours and prices on the museum's website.