Traditional and famous houses and churches with blue domes over the Caldera, Aegean sea in Santorini

(10:23 a.m. EDT) -- Greek cruise line Celestyal Cruises plans to extend its season to 10 months next year and add overnights in Mykonos and Santorini -- a first for the line -- following passenger demand.

The line aims to start cruising in the Aegean as early as February and cruise through to November, possibly adding winter-sun destinations such as Cyprus and Israel.

"Our aim is to sail year-round," explained Kyriakos Anastassiadis, CEO of Celestyal Cruises. "We're going to start by extending the season by a couple of weeks either side, so by 2019/20 we will be sailing year-round.

"We're looking at Southern Med ports, Cyprus and the Holy Land, as possible new destinations. We can easily do that with two ships."

Celestyal currently operates three ships, however it loses its chartered ship -- Celestyal Nefeli -- in mid-November. It gains Thomson Majesty (which has been on charter to Thomson/Marella) at the same time. However, it is not clear what the line plans to do with Majesty at this stage.

It is also bringing Celestyal Crystal back from Cuba in 2018, after trialling it there year-round this year. Anastassiadis blamed the uncertain weather in the Caribbean for the decision.

Crystal -- which featured in the second series of "Cruising with Jane McDonald" last month -- will offer new seven-night "Idyllic Aegean" itineraries, featuring two overnights for the first time: in Mykonos and Santorini.

"Mykonos and Santorini really come alive at night so it makes perfect sense to spend the night in those places," explained Anastassiadis. "Passengers were asking for this, and if you think about it, it's amazing value -- even if you can find somewhere to stay in either of those places in high season, you're looking at hundreds of euros a night."

Anastassiadis also confirmed that Celestyal would continue to call in at Turkey for 2018, though just at Kusadasi for Ephesus. It dropped Cesme this year, and has not called at Istanbul since 2016.

He said: "Turkey is an important market to us. It's not just a port of call, it's a source market and we serve the people there. Turkey doesn't have its own cruise line, so we fill that gap."

He added: "The industry continues to shun this part of the world, we continue to service it."

Anastassiadis said after a tough 2016 and first part of 2017, both ships have been sailing at full capacity since July -- with forward bookings 60 percent up on last year.
"The Americans stayed away last year due to the instability in Turkey, but I think there is a realism that these terrible incidents can occur anywhere, and as a result we've seen bookings from the U.S. come back, particularly group bookings."

Celestyal has an option for passengers to get off at Samos (which is Greece) in the morning if they wish, and get back on when the ship leaves Kusadasi at lunchtime.

--By Adam Coulter, Managing Editor, U.K.