Major work to upgrade Rothesay Harbour “will lead to some disruption” with operations due to start next week.
The work will support the future of the pier by preparing it to accommodate larger, more powerful vessels than the original pier was built to withstand.
Work will start Monday, May 20 and should take nine months to complete, but this is dependent on the weather and supply of materials.
While the work is ongoing, the second daily sailing from Rothesay and the final sailing from Wemyss Bay will be cancelled.
Additionally, to allow access to the site, the berth will not be available overnight, meaning one of the Bute ferries will remain overnight in Gourock.
Director of strategy and change for CalMac, Pauline Blackshaw, said: "We appreciate the efforts made by the council to carry out these works overnight but recognise this will still lead to some disruption for customers.
"As we can only accommodate one of our two vessels at Rothesay overnight, the other will berth nightly at Gourock. Consequently, we must cancel the second daily sailing from Rothesay and the final sailing from Wemyss Bay.
"We fully appreciate the inconvenience this may cause our community and have made every effort to reduce disruption.
“We are committed to maintaining a full service on key dates such as Bute Fest in July, and the Bute Highland Games in August.
“We'll be in regular contact with the council and the local community whilst the works are ongoing."
Stabilisation works at the harbour include constructing a 143m wall from the eastern edge of the original harbour wall to the overnight ferry berth.
This will help stabilise the main structure and prevent any potential sliding or further loss of fine materials from the seabed behind the wall.
There will also be repairs to the surface of the harbour where there has been visible settlement.
Argyll and Bute Council has appointed Shearwater Marine Ltd to undertake the £1.9m stabilisation project which will see them work overnight to minimise disruption to ferry operations and day-to-day travel for Bute residents and visitors.
The contractor will mobilise at the harbour during the week commencing Monday, May 20 and the first dive will be on Monday, May 27.
Chair of Argyll and Bute Harbour Board, Councillor Ross Moreland, said: “It’s welcome news that work is about to start in Rothesay Harbour.
“The pier has played an important part in the island’s history and will continue to play a role in its future, through supporting the economy, transport, and tourism.
“With that in mind, we have arranged to halt the work during key events such as Bute Fest and the Bute Highland Games.
“This will enable CalMac to return to its full ferry service.”
The upcoming work builds on previous investment at the harbour to minimise scour and mitigate damage caused by vessels over the years.
Scour is when the seabed is dug out by vessels moving the water and creating channels against the harbour wall.
To do this, the council installed a wavescreen which prevents vessels moving the water and creating scour and protects the harbour wall.
Regular updates will be available on the council website, and through community, and harbour user groups.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here