Jersey Fire and Rescue says emergency services have been delayed reaching a casualty on the beach because of cars parked on the slipway.
JRFS says there was an incident at the weekend where parked vehicles were in the way.
In a social media post, Station Commander Channing said: “This behaviour is putting people at risk. If we need to rescue people found unconscious in the sea, every second counts. If the emergency services cannot get to the casualty in good time, this life-threatening situation can become fatal.”
He's reminding people to leave enough space for large rescue vehicles to access and manoeuvre around the slipway.
Motorists should park according to the signs on the slip which tell you whether parking is allowed and on which side to park.