Whitsand warning

Routine dredging maintenance of the approaches to Plymouth’s naval dockyard was carried out from around 1-23 March. The take was disposed of in the Navy’s allocated dumping area in Whitsand Bay, three-quarters of a mile south of the wrecks.

During the disposals, divers reported “plumes of dumped silt on the surface of the bay and reduced visibility on the wrecks”, Whitsand Bay conservation campaigner David Peake told Divernet.

There were “noticeable layers” of silt hanging in the water such that, on one occasion, divers were “reaching the Scylla and not diving because of blackwater conditions”. The silty water column had coincided with “the first minor plankton blooms” of the season, worsening the effect further.

A concern is that, depending on weather and sea conditions, deposited silts may continue to be fanned and affect visibility for some time to come – including the forthcoming busy Easter period.

At the beginning of April, said Peake, divers from the University of Plymouth dived the Scylla to find just 6-8m of visibility, despite quiet sea conditions. Silt covered the wreck’s decks and bridge.

“There has been a noticeable difference to the visibility to the east of Plymouth, which is far better,” added Peake.

Divers thinking of visiting the area might be advised to obtain the latest diving feedback on underwater conditions, which should filter through the area’s various dive centres and charter boat operators.

The MoD’s current licence for dockyard dredging and Whitsand dumping was issued in February and is valid until 8 January, 2011, said Peake. There had been “no announcement” of the recent operation and it remained “unknown as to when further dumping will take place”.

When any dredging operation is imminent, however, divers may be able to obtain confirmation of operations from the Queen’s Harbour Master, Plymouth, under whose authority the dredging takes place (QHM General Operational Enquiries – 01752 836953).

QHM would also be aware of any diving safety warning over the Scylla in relation to silting and visibility, though none has been issued since the decommissioned frigate’s sinking in March 2004.

The wreck’s bridge, helicopter hangar and certain parts of higher internal decks feature large, clear openings and little clutter, and have been accessed safely by many divers. But an inquest is expected soon into the 2007 deaths of two, David White, 42, and Kaye Moss, 43, who penetrated further into the wreck and could not find their way out again after, it was thought, kicking up silt.

At the time, Devon and Cornwall police were looking into possible links between silting levels in the ship and naval dredging and dumping activities. Their findings are likely to feature at the inquest hearing.