Only one Island beach has been recommended in the 2008 Good Beach Guide released today (Friday).
But while Derbyhaven receives praise, four local beaches have failed the European legal minimum standard.
Although more beaches overall continue to improve, the Island figures mirror those in the UK.
Dr Sue Kinsey from the Marine Conservation Society cited a wet summer as one of the main factors:
Researching your Manx family history can be a very interesting and rewarding hobby. Trace your roots in the Isle of Man with our helpful of guide.