One of the first books that I have re-read on the quest around Britain is one which is based on the remote islands of the Outer Hebrides. Two boys on a school camp are suddenly adrift as a result of an unexpected trip on their inflatable raft.
Ian and Dougal are peacefully fishing on their raft when the turburlence in the water around the shoal of fish is suddenly increased by the arrival of a bottle-nosed shark. The two boys are experienced enough to realise that they are in no danger of being deliberately attacked by the large creature. However, what they are not expecting is that the sudden surge in the water is going to cause a tremendous and near catastrophic capsize of their safe and dry perches. They are both thrown overboard and Ian is unfortunate to lose consciousness when his head hits a part of the outboard motor which hangs below the rubber skin. Dougal is left with an unconscious friend and a tremendous struggle just to get back on board the flimsy craft. Danger increases when he has to abandon his life-jacket in order to plunge beneath the dinghy and try for his friend's rescue. Dragging Ian to the surface and then forcing him on board takes all his strength and both boys are subject to the bitingly cold wind and drifting further from their camp-site on their lonely island.
Dougal tries to cope with his unconscious friend and then has to abandon him again when he realises that his only hope of getting aid is to swim ashore on to a tiny islet where he has spotted a red-haired man.
A rescue is quickly followed by a whole series of further difficulties when the man and his companions have every reason for secrecy and no wish to complete their rescue and go for aid. The exact location of the island is in sight of the lighthouse at the foot of Barra. Cave of the Cormorant by Arthur Catherall contains some very effective descriptions of fights in a cave and on board the Cormorant.