There is only one 24 hour police station on the Isle of Wight. All the stations in West Wight get an hour long visit every third day by a bobby sent out from Newport to call into each of the locked up nicks, open the front door and receive any visitors, after exactly an hour he locks the door and drives onto the next station. The opening hours are published on the doors.
When we had a pub on the IoW I was surprised to get a call one night from another landlord to tell me to warn the regulars that the rozzers were on the prowl that night. We had only been on the island for three weeks but it all became clear when one of the regulars told me that the system worked by a series of calls made whenever the area patrol car was seen getting off the Portsmouth to Ryde ferry. Each pub had three or four others to call and spread the word. Apparently the Island force (which is part of Hampshire) had neither the manpower nor the equipment to breathalize anyone so a team was sent over from Pompey on average once a month. In order not to set a pattern the "visits" were random hence the early warning system. Anyone arrested was taken to Newport nick and the team spent the night processing all those caught, returning to Portsmouth on the early morning ferry.