Guernsey Police are on the hunt for those responsible and a spokesman said the facilities had been rendered useless by the damage caused.
The damage is believed to have been caused between 4pm and 5pm on Tuesday.
'This mindless vandalism was carried out in broad daylight at a busy location,' said the police spokesman.
'The weather was good at the time and, as such, we believe there may be members of the public who saw or heard something that could help our investigation.
'As a result of the damage caused, all toilet facilities are no longer usable and will be out of action until they can be repaired.'
