The Gry Maritha will return to scheduled service on Monday May 13th.
Next Friday's (May 10th) sailing of the Mali Rose has been cancelled to make way for the Gry to carry out her required sea trials to ensure she is "fully operational after extensive work".
The Gry has been undergoing a five-year survey during the Mali's three-month familiarisation period. It was announced last month that the Mali will cease operation and be disposed of as soon as possible.
The Isles of Scilly Steamship Group also reminded customers that it cannot accept freight on the Scillonian when operating double sailings on Friday May 3rd and Monday May 6th.
This will also apply on all Scillonian double sailings for the remainder of the year.
The company said: "We are extremely sorry that we have had to cancel Friday 10th May’s sailing, but this needs to be done to ensure that the Gry Maritha is fully prepared as we currently have a limited number of skilled and familiar trained staff to operate both vessels at the same time."