Dangerous for shipping, but ideal for sea picnics.The disappearing island, as the Zanzibar people call it, can give a lot of positives.The main thing here is to know the time of tides so that:1 - be able to swim low water when the island has its largest size, and it is more convenient to dive to the corals,2 - give time to specially trained boys to prepare dishes of traditional Zanzibar cuisine, ie assorted fruits and grilled inhabitants of the sea depths, and3 - have time to get into the boat before the high water for a while will cover the island from human eyes.