Update: 12:50

Wreck off Mull yields 17th-century cannon
Archaeologists from the University of St Andrews have discovered a 17th-century iron cannon, thought to be the only one of its kind still in existence, in the wreck of the Swan , a small Cromwellian warship lost off Mull in 1653. Colin Martin, who has been excavating the eroding wreck for 10 years, said the cannon had the initials of John Browne, King Charles I's gunfounder, on it.