Sheephaven Sub Aqua Club Notes

Sheephaven SAC divers conducted another historical snorkel to an ancient site locked behind a water barrier last Sunday morning, this time visiting the pre-historic Ring Fort on Doon Lough.

The Claire Mc Geever led snorkel party crossed the secluded lake near Portnoo having first been kindly given access across the lands of the landowner, Mr Mc Hugh. Doon Lough is situated at an elevated site, which provided an ideal location for the original builders of this pre-historic fort, affording excellent all round protection from all that might threaten them. The distance from the shore to the island fort was over 500m with water temperature that was recorded on the day at six degrees Celsius, while in-water visibility was no greater than a metre and consequently the depth of the lake was not determined.

Initially as the snorkelers set out from the shore the view of the Doon Fort was obscured but soon the full scale of the ancient Fort came into sight as a testament to people who built it thousands of years ago. The bedrock that surrounds the lake is dominated by Schist laid down during the Daladrian period, with outcrops of Metadorite Schiststone to the north and west and another outcrop of Appinite Suite of intrusive rocks to the south; these outcrops were laid down during the Devonian period of rock formation.

Doon Fort completely covers the island it is located upon with walls that are 4.5m tall and 3.5m thick at their base and a diameter of around 30m, while the fort also contains a series of passages built into the walls. The material used to build the fort appears to be predominately sedimentary shale with larger rocks used to create a base that extends out into the lake. It appears that the island itself was at least partially constructed with the use of these much larger stones, while the walls themselves are built of much smaller hand size stones.

By the 16th Century the fort had become the stronghold of the O’Boyle’s and was the scene of the death of Conor O’Boyle, slain by a rival O’Boyle family in 1530. Doon Fort is similar in construction to other Irish dry-stone wall forts such as Dun Aeugus in the Aran Island and An Grianan Aileach in eastern Donegal and is described by a plaque on site as a communal place of refuge in per-historical times.

Donegal County Council in the early 1950,s repaired the walls of Doon Fort however today a portion of the walls has fallen into disrepair and has partially collapsed. Sheephaven divers are fortunate to be able to access these remote sites, hidden away behind a watery barrier and it is intended to visit some other fortified per-historic sites around Donegal, whether that might be in the county’s lakes or around the coast.

Meanwhile Sheephaven diving continued under the leadership of Kevin Boylan who took a dive party all the way up to Campbell’s Bed in Mulroy Bay, where a one-stick dive was conducted thanks to the presence of a dry-coxswain in the person of Agnes Westwood.

The 20m dive was for a dive times of over forty minutes in water temperatures of six degrees Celsius, water visibility was reasonable a at least five metres of horizontal visibility. This site is renown for the presence of some excellent lobster specimens, as well as the fighting lobsters video recorded in the past. On Saturday morning some of the divers were fortunate enough to once again encounter these lobsters out the open.