VOLUNTEERS WATCHED in dismay last weekend as the Millennium Stone slipped through its binding straps and sank into Milford Haven.
The stone was continuing its journey along Milford Haven out into the Bristol Channel strapped to the Neolithic-style boats or currachs built especially for the £100,000 Heritage Lottery funded project.
Progress was blighted by high winds, which made the operation dangerous.
'Health and safety experts advised us to turn back towards Milford, ' said Philip Bowen from community group Menter Preseli. 'So we turned about.'
But within moments one of the straps that held the 4t bluestone snapped and remaining binds loosened, letting the stone sink 16m to the seabed.
'We have a GPS fixing on the stone, ' continued Bowen, 'and we've contacted the ports authorities, as we're hoping to make a rescue mission.'