New Zealand could be pricing itself out of the benefits of a busy cruise ship season

The season is underway - with the Diamond Princess docking in Lyttelton this morning, after being in the capital over the weekend.

But the New Zealand Cruise Association expects port calls and passenger numbers to be down 20 percent, overall, this year.

Chief executive Jacqui Lloyd says that's the result of increases including the visitor levy, visa costs and port fees.

She says each individual cost on their own makes sense, but once they're layered together it makes New Zealand an expensive place to visit.