Police are set to strip off - to help catch prowlers who are demanding sex from bathers on a nudist beach.
Studland Beach has been a naturist resort for decades
Officers hope by shedding their uniforms they can mingle with others using Studland Beach in Dorset.
They want to deter strangers who have approached bathers after the resort was wrongly branded as a venue for exhibitionist sex, known as "dogging".
However, police chiefs say undercover constables may wear swimming costumes or trunks and will not be naked.
The operation is backed by British Naturism and Studland United Naturists.
Chief Inspector Nick Maton told the BBC News website: "There has been concern about the activities of several predatory males and concern from nudists that they were being approached.
"This was worrying the naturist community. To give an example, one naturist couple using the beach had actually written in the sand in front of them 'no pervs', so they would not be approached."
Last summer, 16 people were arrested for outraging public decency at Studland Beach, which is managed by the National Trust and has been a naturist resort for decades.
Studland Beach Users Action Group, a partnership of police, naturists and the National Trust, has produced a leaflet deploring those who "through sexual misconduct threaten to bring naturism into disrepute".