The John Preston

The wreck of the Welsh schooner John Preston, built in 1855 in North Wales, lies on a ledge in 14-18 metres of water at the point of Rubha Dearg, 1 mile west of Lochaline. The site is locally known as the \’Slate Wreck\’ because many divers know this wreck as nothing more than a pile of slate. But, there is much more to be seen than that!

General site plan of the wreck in relationship to the seabed. The John Preston was built under special survey at Bangor, North Wales, in 1855. She was of wooden construction with iron bolts and is recorded as being schooner rigged. Her dimensions are first recorded in the Lloyds Register of Shipping for 1863/64 as: Length 73ft 3in; Breadth 19 ft 5in; Depth 11 ft 7in; Net tonnage 126 tons.

The John Preston changed ownership several times during service which saw her engaged in coastal trade from North Wales. She went through several refits (1876, 1878) and upgradings/downratings by Lloyds. The John Preston sank on the 2nd of December 1882 while on a journey from Port Dinorwic to Fraserburgh (on the East Coast of Scotland) with a cargo of slates. Reports indicate that she was riding out a force 10 southwesterly gale in Scallastle Bay when her anchor cable broke and she was blown across the sound onto the rocky southern shore of the Morvern peninsula. Her masts were the only thing visible after the sinking and her master, W. Jones, and crew of 5 were all saved.

Investigations by SOMAP

Several salvage attempts have been made on the slate cargo of the John Preston. These have exposed the hull structure for all to see. SOMAP volunteers have been working to record the ship before her hull timbers deteriorate further. By establishing a survey grid and fixed datums over the hull structure, divers have been able to lay tape measure lanes as a guide for recording.

Plan of the John Preston.

The site plan above shows that the John Preston lies over on her port side at an angle of 30° to the horizontal, with the result that the turn of the bilge on the port side is still buried. At the east end of the site, the frames and planking narrow towards her stern and the stern post remains visible. Additional evidence in the form of a possible gudgeon / pintle strap and stern cabin fittings – a deck light (see drawing below) and small oven (top plan object ‘f’) confirms that this was the stern.
Deadlight originally a fitting in the deck to allow light into the living quarters below.

Drawing of a deadlight from the John Preston. An anchor at the west end of the site is located towards the bow of the wreck. The recorded length of the keel (18.90 metres) is at odds with the 19.80 metres that would be expected of a 23 meter long vessel. The missing metre may be accounted for by the breaking off of the stem post, apron and deadwood and the subsequent erosion of the thinner forward end of the keel. It may be that the ship broke her bows on impact with the shore, and as she sank, spilled much of her cargo and heavy deck fittings forward. The presence of a bowsprit cap some distance to the west of the site tends to confirm this suggestion.

Down slope of the main hull structure, several large iron features remain, including the main anchor winch (plan object 005), several hollow iron pipes (plan objects 003;004) associated with the bilge pump system and some rigging fittings. The bilge pump housing remains in place (plan object C) close to the main structural timber, the rider keelson. Some iron knees can also be seen (plan objects 002;001). These are all that remain of the ship’s deck; the wood has long since disappeared.

All the artefacts from the John Preston have been recorded in situ although a few objects were lifted, drawn and photographed on land before being reburied on the site. SOMAP does not have any funds to conserve underwater finds. The only find which has been kept ashore is a small pulley wheel. This object was recovered by divers and left to rot at the Dive Centre. SOMAP member Dr Barry Kaye kindly offered to conserve this object. It has been properly recorded and returned to Lochaline Dive Centre for display.

In the future, the site plans of the John Preston will be worked up into an information leaflet about the wreck, and a site plan for divers to take with them underwater. SOMAP plans to continue survey work on this site and to monitor the wreck as it changes over time. The wreck will also form the cornerstone of future SOMAP projects, teaching budding underwater archaeologists how to record shipwrecks.

The John Preston is a wreck of local importance and everyone is encouraged to dive this site. However, we ask that divers who do visit this site do not remove anything from the seabed. This wreck is far better off being left on the seabed where other divers can enjoy it in the future.


Philip Robertson, who organised SOMAP for many years.
Steve Webster (site director 1999).
Simon Adey Davies (assistant 1998,2000).
SOMAP participants, in particular Barry Kaye, Jo Cook and Geert Devogel, who have supplied drawings and plans for this page.

The John Preston was investigated as part of the Sound of Mull Archaeological Project course for many years. This course is still run every summer by the dive centre; see our NAS Scotland link for further details.