3.7.5	AREA 5 - PENTLAND FIRTH
3.7.5.1	This region has been isolated from Region 4 as being an entity of its own, deserving of special attention. It is an area notorious for very strong tidal streams (up to 12 knots) and poor weather, which together, in certain conditions, can produce a truly fearsome combination. It constitutes one of the main east/west channels between continental Europe and the Atlantic Ocean and, as such, is greatly used by commercial traffic, much of it oil-related. Its coastlines are rocky and precipitous and the centrally positioned island of Stroma, although well marked, presents an additional hazard. There are 3888 traffic movements per annum over 164 routes within a 10nm radius of Stroma LH- see figure 6 below.

Reproduced from Admiralty Chart 1954 by permission of the Controller of Her Majesty's Stationery Office and the UK Hydrographic Office (www.ukho.gov.uk) NOT TO BE USED FOR NAVIGATON

Figure 6: ShipRoutes overlay for the 164 routes identified within 10.00 nm of Stroma LH.

3.7.5.2	The Firth has been treated as a channel between two gateways; an eastern gateway between Duncansby Head and Pentland Skerries; and a western gateway between Dunnet Head and Tor Ness. It is noted that Tor Ness light now has an increased range of 17 miles, and that Cantick Head, at the narrow southern entrance to Scapa Flow, has a present range of 18 miles. Considering the importance of the main channel, the extreme conditions sometimes experienced and the predicted increase in oil-related traffic in conjunction with very strong efforts to establish a container hub in Scapa Flow, it is proposed to maintain a highly efficient, reliable system of Aids to Navigation in the area.
3.7.5.3	There are no GLA buoys in this region.
3.7.5.4	A substantial response to a consultation letter sent to Harbour Masters within this area would indicate that the present mix of AtoN maintained by both NLB and the LLA's meet the needs of the mariner. This paper is intended for discussion at the NLB Navigation Committee, prior to forwarding for further User Consultation and discussion at inter-GLA Review.
3.7.5.5	The main changes proposed for Area 5 are, as follows:

• Lother Rock - Proposed change of character to Fl W 2s (move away from N. Cardinal character).
  
• Pentland Skerries - Discontinue Fog Signal
  
• Stroma - Discontinue Fog Signal.
  
• Ruff Reef - Proposed change of character to Fl W 10s (move away from Iso Danger character). Hand over to Orkney Island Council
  
• Stroma - St.Johns - Establish new minor light on reef with character Fl W 5s and a range of 3 nautical miles.