CAVRA Service Materials



  1. About Us
  2. Events
  3. Radio Procedure
  4. Cliff Rescue Drill
  5. Communication Equipment


  1. Conservation and Access
  2. Navigation with Map and Compass

III.  First Aid

  1. Priorities
  2. Resuscitation, plus
  3. Bleeding, Shock
  4. Casualty Examination, plus
  5. Effects of Heat and Cold
  6. Medical Conditions
  7. Self-Assessment: Multiple Choice Test

IV.  College

  1. The Local Coast
  2. Tides


1. The Local Coast

To view detailed OS maps of the area, on
which 1 square = 1 km, click on one of the
regions; (each image is about 200 kB.)
w e s t
c e n t r a l
e a s t

For a roadmap of the area, click here.
( 1 square = 10 km, 78 kB. )

The table below lists, from East to West, the access points, landmarks and other special features along our part of the coast which all members of CG-Service should be familiar with.

The path on the cliff-top along most of our part of the coast is maintained by an organisation called the ''Heritage Coast''. Their members know the area extremely well and have always been very cooperative. A key for all the Heritage Coast gates should be in each landrover.

Legend:     access is possible       get cut off by tide early     "unofficial place names"

E A S T  
Font-y-gary Caravan Park  
Leys Bay  
Breaksea Pointby the Power Stationwater inlet for the Power Station
Gileston Beach, in Limpert Bay  
Boverton Beach,
in Summerhouse Bay (= Penry Bay)
access through Camp or down the footpath from ...  
Summerhouse Point Heritage Coast gate on access road, where there is the old ... 
CG-Lookoutdisused; access via Boverton Mill Farm 
Stout Point  
New Way Stair a steep scramble; access via Rosedew Farm, then along field; (N.B.: the farmer does not like us to drive across his land) 
Pigeon Point  
Llantwit Major Beach (= Col-huw Point)Lifeguard Station 
Dimholea drop in the cliff, a steep scramble 
Tresilian Bay access along the private road, through gardens 
Reynard's Cave  
Stradling Stepsfairly steep steps 
''Demo Cliff East/ West''  
St. Donats BayRNLI Station, slipway 
St. Donats Point  
Lighthouses N.B.: Nash Point is on the other side of ... 
Cwm Marcross (= Nash Cwm) ''cwm'' is just the Welsh word for a valley 
Nash Point  Nash Sands stretch West; the other side of Nash Passage marked by East Nash Buoy
Cwm Nash (= Monknash Cwm) access along foot path -- parking/ rendezvous point at New Mill Farm 
Whitmore Stairs an old rock-fall, by now a very steep scramble 
Wick Beach  
Cwm Bach iron ladder -- the top now difficult to access by vehicle 
Cwm Mawr waterfall; not an access point 
Dunraven Steps, in Temple Bay comfortable to walk; Heritage Coast gate on the road to the top of the stairs (key in the vehicles) 
Witches Point popular for fishing from 
Southerndown Beach (= Dunraven Bay)   
Little West Hotel an ILB landmark; now an old people's home 
''Big Ogmore'' has been popular for climbing, but very loose rock 
Castle Rock in the sea 
West Farm by the road 
the Deeps caves at sealevel; used by fishermen for getting bait 
''Little Ogmore''  
''Ogmore Crack'' easy access to the waterline everywhere to the West of here 
Brig-y-don Hotel an ILB-landmark; can drive down to the cliff top from here 
Ogmore beach Heritage Coast gate at East end of carpark Tusker Rock, about 2 km out at sea, covered at high water
Ogmore Lifeguard Station,
or Pen-y-bont SLSA
the Flats a large area of gravel covered at high water; dangerous tidal currents 
bank of the Ogmore River with the ruins of the old castle 2 km upstream 
W E S T  


2. Tides

A characteristic of our local coast is the great difference in the water level between High Water and Low Water -- up to 15 m. The interval between one High Water and the next is approximately 12 hours 25 minutes. The tidal movement of water is due to the gravitational influence of the moon and, to a lesser extent, the sun.

Something to think about: if the earth turns underneath the moon once every 24 hours, and high tide is due to the moon attracting the water in the sea, why are there two high tides per day, i.e why is the water high on the opposite side of the earth from the moon as well?
When the sun and the moon are 'pulling in the same direction', High Water is especially high and Low Water especially low; in practice these spring-tides occur two days after a full or a new moon, i.e. about every 14 days. The opposite are neap-tides: half-way between two spring tides, High Water is less high and Low Water less low. The highest spring tides occur in spring and in autumn, when the earth is closest to the sun.

It is important to keep in mind how quickly the water level changes at certain times between High and Low Water: fastest when it is half-way up or down. The Rule of Twelfths states that in the approximately six hours between Low Water and the next High Water (or between High Water and the next Low Water), the water rises (or falls) by 1/12 of the total height difference in the first hour, by 2/12 in the second hour, then by 3/12, 3/12, 2/12, and 1/12 in the remaining hours.

I used to have a table of the times of High Water at Barry on this website, for use at the College. The information came from WXTide32, a convenient Windows port of a Linux program. But having been informed by Miss T J Wenham, the Assistant Copyright Compliance Officer at the UK Hydrographic Office, that using the harmonic constants required by WXTide32 infringes Crown copyright, I have had to remove this service from my page.
2nd-year students in CAVRA should in general know the approximate time of the next High Water, especially of course when they are on call-out duty, and perhaps also whether it is spring- or neap-tides. Note that tides are also especially high when the wind is blowing from the West.

Map of the area from