Visa requirements Tanzania (dar es Salam & Zanzibar

Can anyone help please? It is not clear on the Tanzanian web site whether we need 2 Visas (crazy!) or just one for our cruise which visits noth ports. The official website says a visa is for a SINGLE entry. There are no Transit visas, so I am hoping that it is only one that is required. I know that when we cruised in India we had to have a multi entrance visa, but TZ does not issue these. I have received conflicting replies from the Cruise Company and my TA's visa provider company.

I would ask this on the Ports of Call board which covers Africa. EM