Coastguards say jet skiers have been riding deliberately towards swimmers and even children playing in the sea, putting them in danger.
The warm weather has seen an increase in the machines being used along the coast but some are flouting by-laws and are riding too close to the beach.
Charlotte Wilkins reports and speaks to Solent coastguard Carey MacKinnon, jet skier Simone Smith and watersports enthusiast Paul Richards.
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Friday's forecast for the east of the region
Friday's forecast for the west of the region