Humberside Police officers are urging young people to think twice before putting themselves in danger in water and near railway lines.
Police advice for beaches includes only to swim between red and yellow flags, as these are the areas patrolled by lifeguards on those beaches that have them.
A police spokesman said: “Think twice about using inflatables in the water – as it is easy for them to be blown out to sea quickly.
“If there’s an orange windsock flying, it’s especially dangerous. Be aware of tide times, to ensure you don’t get cut off, and supervise younger children.”
The advice, which is part of the force’s Stay Safe Over Summer campaign, also includes warnings about swimming in canals and rivers, and about trespassing on railway lines which can lead to tragic consequences.
A spokesman for British Transport Police said: “Up to 60 people are killed on the railway every year by crossing the tracks, taking short cuts or playing chicken.
“Trains can travel at 125 mph and take the length of 20 football pitches to stop. If you are in the way the train won’t stop - the driver will not see you until it’s too late.
“Vandals putting obstructions in front of trains, hanging concrete blocks from bridges and throwing stones are sadly daily occurrences.
“These crimes can lead to serious injury or death and can even derail trains.”
Police say there are plenty of activities going on across the force area for young people of all ages and with a wide range of interests to get involved with. Sgt James Main, from the force Youth Engagement team, said: “There’s no need to put your life – and the lives of your friends – in danger by taking unnecessary risks.
For more information visit the Stay Safe Over Summer page on the Humberside Police website.