Follows reports of some 'near misses'
People are being warned not to jump into or swim in the Island's harbours.
Coastguard officers and harbour officers have reported some cases over the past couple of weeks, following the recent spell of warm weather.
They're particularly concerned about children or young people, who they say are perhaps unaware of the dangers of jumping into very cold, and deceptively shallow, water.
The reminder comes after what they describe as 'some near misses' with berthed vessels.
It is an offence to swim, bathe or dive from any harbour pier or any part of a harbour which lies within a pier head, and failure to comply with instruction given by a Harbour Officer can lead to prosecution and a fine of up to £5000.