I fully support Liberation Scotland‘s UN mission to have Scotland recognised as a colony. Who ever thought it wasn’t?

However, their other agenda to abuse the SNP and everything it has achieved in government, is risible and divisive. Here’s the latest – bloody catamarans again!

By no measure, based on evidence globally, is Scotland’s ferry system failing. It’s the best in the World.

https://talkingupscotlandtwo.com/2025/03/06/tory-mp-with-worst-local-ferry-service-in-the-uk-feeds-labour-opportunity-to-lie-about-best-ferry-service-in-the-uk/

https://talkingupscotlandtwo.com/2025/12/23/calmac-youngest-ferries-best-funding-and-most-staff/

Simlarly, catamarans are not the answer.

Here’s the answer:

Throughout much of 2024, the Herald worked with opposition politicians in a campaign aimed at undermining CalMac and, by association, the SNP’s competence in government.

We, at TuS found several reports of the unsuitability of catamarans across the globe, even in milder conditions than off the West coast of Scotland and today we have used the X AI platform Grok to finally answer the question – Are mono hull or catamaran ferries better for the West Coast of Scotland island routes?

The findings were unequivocal in favour of the mono-hulls:

Choosing between mono hull and catamaran ferries for Scotland’s West Coast island routes depends on several factors, including sea conditions, route characteristics, passenger comfort, and operational efficiency. Here’s a concise comparison based on available information and the specific context of the West Coast of Scotland:Mono Hull Ferries

• Stability in Rough Seas: Mono hulls, with their deeper drafts and heavier displacement, are generally more stable in the rough, unpredictable waters of the West Coast of Scotland, where strong winds and high waves are common, especially in winter. They are better suited for handling adverse weather conditions, which is critical for year-round reliability on routes like those operated by CalMac.
• Capacity: Mono hulls typically offer greater capacity for vehicles and passengers, which is advantageous for high-demand routes to larger islands like Skye, Mull, or Arran. They can carry heavier loads, including freight, which is vital for island economies.
• Fuel Efficiency: Mono hulls are less fuel-efficient at high speeds compared to catamarans but perform well at moderate speeds typical for longer routes. Their fuel consumption is more predictable in rough conditions.
• Maneuverability: Mono hulls are less agile than catamarans, which can be a drawback in tight harbors or when quick turnarounds are needed.
• Examples: Most CalMac ferries, such as the MV Caledonian Isles or MV Isle of Mull, are mono hulls, designed for durability and capacity on routes exposed to open sea conditions.

Catamaran Ferries

• Speed and Efficiency: Catamarans are generally faster and more fuel-efficient at high speeds due to their lighter construction and dual-hull design, which reduces drag. This makes them suitable for shorter, high-frequency routes or calmer waters, such as sheltered routes to smaller islands or during summer months.
• Passenger Comfort: Catamarans offer a smoother ride in calm to moderate seas due to their wide beam and reduced rolling. However, in rough seas, they can experience more pitching and slamming, which may reduce comfort and increase seasickness for passengers on exposed routes.
• Maneuverability: Their twin-hull design allows for better maneuverability in ports, which is beneficial for quick docking and undocking in smaller harbors.
• Capacity: Catamarans typically have lower vehicle and freight capacity compared to mono hulls of similar size, which may limit their suitability for high-demand routes or those requiring significant cargo transport.
• Examples: Catamarans like the MV Alfred (operated by Pentland Ferries in the Orkney region) have been used successfully in Scotland but are less common on CalMac’s West Coast routes due to capacity and sea condition constraints.

Context-Specific Considerations

• Sea Conditions: The West Coast of Scotland, particularly routes to the Outer Hebrides or exposed islands like Barra, experiences frequent storms and high swells. Mono hulls are better equipped to handle these conditions, ensuring reliability and safety. Catamarans may struggle in severe weather, leading to more frequent cancellations.
• Route Length and Demand: For longer routes (e.g., Oban to Barra, ~5 hours) or high-capacity routes (e.g., Ardrossan to Arran), mono hulls are preferred due to their ability to carry more passengers and vehicles. Catamarans may be viable for shorter, less busy routes, such as between smaller islands or in sheltered waters like the Firth of Clyde.
• Infrastructure: Many West Coast ports are designed for mono hull ferries, with loading ramps and berths suited to their size and draft. Catamarans may require infrastructure upgrades, which could increase costs.
• Environmental Impact: Catamarans can be more fuel-efficient on certain routes, reducing emissions, but newer mono hull designs (e.g., CalMac’s hybrid ferries like MV Hallaig) are closing this gap with greener technologies.

Conclusion

For the West Coast of Scotland’s island routes, mono hull ferries are generally better suited due to their stability in rough seas, higher capacity for passengers and freight, and compatibility with existing infrastructure. They ensure year-round reliability in the region’s challenging weather conditions. Catamarans could be considered for shorter, sheltered routes or as supplementary vessels for high-frequency summer services, but their limitations in capacity and rough-sea performance make them less ideal as the primary choice for most routes.