Also bear in mind that between June 1st and September 30th, the minimum height over beaches is 1000' AGL within 100 metres on both sides of the shoreline. Not that everyone abides by this rule, but still it does exist.
As berniecta points out, specific authorisations may be granted to fly lower than the prescribed heights, but I guess it's on a case-by-case basis.
I'm afraid ENAC are the only people you should try and talk to in order to request a special authorisation. Not sure what specific ENAC unit you should write to, though
