THE TRANSPORT company will affect anyone who is booked for sailings between the dates of 12 and 29 July.
Irish Ferries have been forced to cancel sailing after the delivery of a new ferry for the company has been delayed.
The boat, called the WB Yeats, won't be able for sailing until July, it is said.
According to RTÉ, Irish Ferries said they would be able to help passengers with bookings later in the Summer.
They said they will be able to aid passengers booked in for the July period on sailings from Rosslare aboard the Oscar Wilde.
Customers have been notified and given a voucher for the inconvenience, with a full refund promised to customers if they cannot fit on another boat, the Oscar Wilde.