THE strategy document produced by Sea Transport Corporation provides a series of examples to demonstrate how their open coastal catamaran vessel designs are superior to anything CalMac has at present.

The national ferry operator's MV Lord of the Isles, with a total length of 84.6m, can carry just 54 cars, while Sea Transport's wider ST 75 design but with an overall length of 75m uses around a third less energy and has a 95-car capacity.

MV Hebridean Isles has a length of 85.2m, can carry 494 passengers and 62 cars but Sea Transport's STS 85, with an 85m length, uses about half of the power required by the CalMac ship, can carry 600 passengers and 115 cars.

Dr Ballantyne says his catamarans would reduce fuel consumption costs by £8.5m a year.

He said: "For the proposed Sea Scotland fleet to achieve the same annual capacity of CalMac service miles represents a 37 per cent reduction in fuel and emissions.

"Extrapolated into car miles with the extra car capacity it is around a 55 per cent reduction.

"Extra capacity allows extra capability and revenue on peak days."