Some caches in this series are away from popular beaches or easy access by other means. It is therefore important that you prepare properly for your trip.
Check the weather forecast and sea conditions before setting out.
Travel with another kayaker, if possible. Let someone know your travel details and anticipated return time.
Dress for the weather conditions, it can be colder on the water than on land. Use sunscreen, hats and long sleeved clothes in sunny weather.
Carry appropriate safety equipment. Wear your life jacket (PFD). Wearing your lifejacket will help keep your head above water and add insulation to your body, keeping you warmer in cold water. Carry a mobile phone (in a waterproof container if needed.)
A sea arch is a natural opening eroded out of a cliff face by marine processes.
Some arches appear to have developed from surge channels, which are created by wave refraction causing the focussing of wave fronts on the side of a headland. More generally, arches develop where waves attack a plane of weakness which cross-cuts a promontory. Caves produced on either side of a promontory may become joined over time to become a tunnel and, finally, an arch.
A striking feature of the cliffs below Le Long Cavaleux is that the headland is crossed by prominent bands of very dark rocks. These are impressive examples of dolerite dykes which were originally molten magma which found it's way into cracks in the much older rock whereupon the magma solidified. These are perhaps the best examples of this type of feature on our cliffs, but a careful examination of other locations will reveal that our cliffs are full of very dark dykes such as we see here, and sometimes lighter coloured or reddish dykes. Another feature which stands out from these views is the reddish colour of the rocks into which the dark dykes intrude. It is known as Icart Gneiss. Some 2,600 million years ago this rock was a red granite, but it then re-crystallised into it's current form under great temperature and pressure. It is not only one of Guernsey's oldest rocks, but one of the oldest in the British Isles or France.
To claim this cache, you need to do the following:
1. Post a photo of you, or your kayak under the arch.(Optional)
2. Email me the answer to the following question:- If you stand in the middle of the arch and look up you will see the narrowest part of the arch. Assuming that the arch erodes at 25mm per year on average, how long before it becomes a stack?
Congratulations to lihoubeachbum FTF