(The conjugation charts are added here)
From Wiktionary: https://en.wiktionary.org/wiki/tembelea
Anatembelea Zanzibar. - He is visiting Zanzibar.
Ametembelea Zanzibar - He has visited Zanzibar.
Alitembelea Zanzibar. - He visited Zanzibar.
Atatembelea Zanzibar. - He will visit Zanzibar.
(yeye) hutembelea Zanzibar. - He goes regularly to Zanzibar
He shall visit Zanzibar should also be accepted as it is common usage