Some horses do well in the heavy conditions and are known as MUDLARKS. Are you a mudlark? The cache is on a tidal island in the estuary. At low tide there is only a 2 metre stretch of water that is calf deep. There is however a lot of mud most of it is not very deep but there are patches that will go up to your knees ( I know this is true). Avoid these patches if you can.
The cache is a an old paint tin which I have tidied to a bush. It is on a high point but the occasionally flood may threaten the cache. Take something to open the tin then reseal it.