By Anna Lindsay
BBC News, Southampton
The prosecution alleged Pride of Bilbao either swamped or hit Ouzo
More than 15 months after three sailors were found drowned off the Isle of Wight, mystery continues to surround the yachtsmen's final moments.
Ferry officer Michael Hubble, 62, has been cleared of three counts of manslaughter and charges of endangering lives under the Merchant Shipping Act, for failing to stop P&O's towering Pride of Bilbao after it was involved in a close encounter with a yacht.
Exactly why Rupert Saunders, 36, James Meaby, 36, and Jason Downer, 35, lost their lives may never be known.
It is all because a key factor of the tragedy is still missing - the yacht Ouzo itself, in which the trio were sailing when a catastrophe happened so suddenly, they had no time to issue a Mayday call.
The small, classic Sailfish 25, which had been in the Saunders family for 25 years, has never been found.
Pride of Bilbao had been heading out of Portsmouth to Spain, when the 25ft (7.6m) Ouzo disappeared in the early hours of 21 August 2006.
Within days the ferry, which carries 2,500 passengers between Portsmouth and Spain, had her hull examined by the Marine Accident Investigation Branch (MAIB) and its black box was taken away.
Mr Hubble, who was in charge of the ferry's bridge when investigators believe Ouzo vanished, was later charged with three counts of manslaughter through gross negligence and engaging in conduct likely to cause death or serious injury - all of which he denied.
What is beyond doubt is that the 37,500-ton ferry came close to colliding with a yacht - Mr Hubble accepts this.
However, he always maintained the ferry did not clash with the boat and he was able to see the mystery yacht sail off in another direction at 0107 BST.
But if Pride of Bilbao did not hit or swamp Ouzo, what could have caused the yacht's disappearance?
An investigation by the MAIB, which investigates all maritime accidents but does not apportion blame, considered the possibility Ouzo sank as the result of an explosion or that the yacht suffered hull failure.
The inquiry found that at least one other Sailfish yacht had lost her keel unexpectedly.
But the MAIB dismissed this theory on the basis that without the keel, Ouzo would have stayed afloat for some time. Despite searches it was never found.
Post-mortem tests also showed no signs of an explosion on the bodies of the three sailors.
One theory, put forward by Mr Hubble's defence team, was that the yacht crossed the path of an oil tanker.
Data analysis from the maritime college in South Tyneside, showed the Crescent Beaune and Ouzo would have reached the same point at 0140 BST.
The captain of the tanker, Alistair Crichton, admitted to jurors he was not on her bridge at the time and broke the law by not having a lookout on duty.
Pride of Bilbao's encounter with a yacht would have happened 33 minutes earlier.
Despite the MAIB investigation, these theories remain unproven.
The MAIB also attempted to investigate the quality of Ouzo's lookout, the condition of the yacht's navigation lights and whether the sailors had hoisted the boat's radar reflector - a piece of metal equipment that sits on a mast and makes small boats more visible on the radar of larger ships.
The yacht had several navigation lights but their power and working order are also unknown, although they had not been replaced since the boat was built in 1979.
In a bid for answers the MAIB, along with the coastguard and police, tried to retrace Ouzo's final moments out at sea in another Sailfish 25 with similar equipment.
Other speculation has included theories that the yacht's lookout had fallen overboard or that the boat had suffered an electrics failure before it succumbed to a collision or capsized.
The last known sighting of Ouzo was at about 1930 BST on 20 August, when the three yachtsmen sailed out of Bembridge, on the Isle of Wight, and headed for Dartmouth, Devon, in calm waters - perhaps a 10-hour sail.
Bill Mitchell, of AA Coombes boatyard in Bembridge, where Ouzo was based, saw her leave.
"I didn't see them [in person] that weekend," he said.
Ouzo was a classic Sailfish 25 (photo www.patrickroach.com)
"I was walking my dog on a beach and just saw the boat leaving the harbour about a quarter of a mile away. I thought 'oh good, they've gone out'."
At 2325 BST Pride of Bilbao set off from Portsmouth and headed for Spain. The sailing was just over two hours late due to a technical fault.
Nearly 36 hours later the body of Mr Meaby, a sales executive from Tooting, south London, was found by a fishing vessel 10 miles south of the Nab Tower, off the Isle of Wight.
An air and sea search subsequently found the bodies of Mr Saunders, also of Tooting, and Mr Downer, of Broadstairs, Kent, five miles south of the island.
They were all wearing lifejackets.
Post-mortem tests showed all three drowned.
Mr Meaby suffered hypothermia first, suggesting he survived for some time in the water.
An inquest into all three deaths has been opened and adjourned.