Ferry operator CalMac has announced that the return of the MV Caledonian Isles - which has been out of service since last February - has been delayed by a further month.

The ship has faced a series of issues including rust and twisted frames.

It had been due to return to the Arran route by the end of April, but that has now been pushed back to the end of May.

Until then, the service to Brodick will continue from Troon with a two-vessel service of MV Glen Sannox and MV Alfred.

CalMac said it had found new issues with the tubes for MV Caledonian Isles' propeller shafts.

The state-owned operator's chief executive officer Duncan Mackison said: "We know MV Caledonian Isles' ongoing absence has caused significant disruption on Arran and the wider network, and that's why we've taken steps to ensure that when she returns, she provides a resilient and reliable service.

"We're in regular contact with Arran's ferry committee and want to reassure the local community that we expect MV Caledonian Isles back soon."

Meanwhile, a further delay to the return of MV Hebrides from scheduled annual maintenance has also been announced.

CalMac said the vessel, which operates on the Uig triangle, requires an extra six days of work to the bow visor and stern ramp.

It is now set to return on Tuesday 22 April.

The current alternative deployment plan will continue until the vessel is back in service.

A huge smoke haze from a wildfire prompted ships on the River Clyde to sound their foghorns on Monday.

Fumes from the blaze near Inverkip in Inverclyde drifted over Greenock, with social media reports saying ships issued warning blasts due to low visibility.

A spokesperson for Peel Ports Clydeport said there was no specific request for sound signals, but vessels are obligated under the International Collision regulations to operate their foghorns when in or near areas of restricted visibility.

Funding has been earmarked for another new large ferry to serve the Western Isles, Scotland's transport secretary has told islanders.

Fiona Hyslop said money was allocated in the budget to replace the ageing MV Lord of the Isles, which serves South Uist, within "about three years".

Hyslop made the pledge at a "crisis summit" called by an island business group which claims economic development is being stifled by ferries disruption.

South Uist has been particularly badly hit by a shortage of vessels on CalMac routes, and is currently served by a ship restricted to just 45 passengers.

West coast ferry services have been under intense pressure as the state-owned ferry operator awaits the arrival of replacement vessels for its ageing fleet.

Winter maintenance has revealed new faults in older ships and forced it to rejig the expected deployment of ferries around the network.

MV Lord of the Isles, which normally sails from Lochboisdale on South Uist to the mainland port of Mallaig, is currently serving other routes and will not return until mid-May.

MV Isle of Mull is instead sailing from the island to Oban, but a fault with its emergency evacuation chutes means it is only permitted to carry 45 passengers instead of the 900 it can normally accommodate.

On the eve of the meeting, the Scottish government announced a £4.4m "resilience fund" to help island businesses during the current difficult period.

A concessionary fare scheme for young islanders will also be extended this summer, giving four free journeys to the mainland for those aged between 19 and 21.

Earlier this month, under 22s in Orkney, Shetland and the Western Isles became entitled to free inter-island travel in a scheme similar to the free bus travel for young people introduced throughout Scotland.

The South Uist Business Impact Group called the "crisis summit", claiming the island had suffered "reputational damage" from years of under investment.

Spokesperson John Daniel Peteranna told the BBC: "When we set up the business group three years ago we didn't think things could get any worse but they have surprised us."

Replacement plans for MV Lord of the Isles, the third oldest large ship in the CalMac fleet, was one of the issues the group was seeking answers on.

Hyslop told the meeting that funding for the procurement of a new ferry was included in the 2025/26 budget.

Another £4m had been allocated for site investigation work for a proposed new ferry terminal on Gasay island, a short distance from the existing Lochboisdale pier.

On the resilience fund, she said help would be "targeted" at island communities worst affected by disruption but that South Uist would "definitely benefit".

During the 1980s and 90s CalMac would typically purchase a new ship every few years but since 2007 the procurement role has been taken on by a separate government owned company, CMAL.

Problems over the construction of two new gas-powered ferries ordered in 2015 contributed to a slowdown in ferry replacement - and much of CalMac's large ship fleet is now beyond its expected operational life.

The first new large ferry in a decade, MV Glen Sannox, entered service in January while its sister ship MV Glen Rosa remains under construction.

In 2022 and 2023 contracts for another four ships were placed with a Turkish shipyard, but these are also delayed, with the first delivery now due in the summer.

Earlier this year CalMac warned it was facing "exceptional" pressures as it awaited the arrival of the new vessels.

The 32-year-old MV Caledonian Isles has been out of service for more than a year for repairs, MV Hebridean Isles had to be retired and other vessels have had problems identified during winter overhauls.

The ferry operator said it had been providing extra sailings from South Uist to Barra to offer an alternative route to the mainland, and it was considering whether sailing times for this option could be extended.