Interislander's troubled replacement ship Stena Alegra has run into more problems.
KiwiRail advised today it had been forced to cancel the ship's sailings yesterday and today due to a "spike in illness among crew''.
All affected passengers were contacted and transferred to alternative sailings, it said. Freight crossings had also been changed.
Today's announcement comes less than a month after the ferry was sidelined for repairs when its hull was damaged in bad weather at the Wellington Ferry terminal.
In January, less than a week after it made its first Cook Strait crossing, it broke down after suffering a partial loss of power while leaving Wellington.