The operator said due to financial issues at the Croatian Uljanik shipyard and a strike by workers, the ship would now not sail until April 13, 2019.
Eclipse had been due to launch on August 31, but this was in July put back to January 2019.
Scenic says it has been in “constant contact” with the shipyard, unions and Croatian government to progress completion.
More than 600 workers though are still required on board each day.
It is understood the main hold up relates to the ship’s engine and core systems.
Announcing the further delay on Tuesday (November 13), it said progress on the ships interiors and other areas had experienced less impact from the industrial action and were progressing “at good pace”.
However, although the specialist commissioning team working on some of the ship’s more technical facets, returned to work progressively last week, Scenic has said it won’t be able to catch up “almost six weeks’ lost time” due to the strikes.
“Scenic acknowledges the regrettable impact this has on guests and understands their disappointment at this change in sailing date,” said the line in a statement.
Guests booked on any affected Eclipse sailings will be offered a full refund and compensation for any other “reasonable associated costs” relating to their travel plans.
It will also provide all guests who rebook future cruise credit to the value of 25% of the cost of their new cruise.
A helpline has been set up on 0161 234 2865 and the line is in the process of contacting guests and travel agents to facilitate refunds or make new arrangements.