@Derek: I don't live by the sea - actually, about 30 miles from the coast. But I have friends in Penang Island who grow orchids just a few hundred metres from the sea and their orchids are thriving! Believe it or not Paph niveum used to grow right up to the high-water mark in its original home in the Langkawi Islands. Needless to say these have all but disappeared having been cleared by collectors.