Either one of the Swiftsure or Trafalgur class Nuclear attach submarines of the Royal Navy slips past Largs on its way to Faslane. This isn't the normal rooute they take, maybe he was sight seeing, I can't tell the difference between those two classes of Submarine so it could be either. Not many Swiftsure's remain in service but at the time this photo was taken in 2008 the first of the New Astute class wasn't yet at sea.
