PATROLS are being stepped up to combat "idiots" on speedboats and jet skis who are putting lives at risk along Weymouth's packed beaches.

Harbourmaster Captain David Stabler says he has taken action to improve safety amid reports of people who are banned from operating craft in other parts of Dorset moving to the resort.

Capt Stabler said: "Weymouth Bay is a huge area with room for all so why do these idiots insist upon operating recklessly among bathers?

"Once again the irresponsible minority are spoiling it for the well-behaved majority."

Unprecedented numbers of pleasure craft - and swimmers - have taken to the sea during the spell of hot weather.

Capt Stabler said he and his staff had run into several inexperienced and belligerent boat users who didn't know the rules governing speed limits and manouevring.

"Unfortunately some of the drivers of these craft fail to see the simple common sense of avoiding bathing areas and are behaving in the most irresponsible manner," he said.

Weymouth Harbour Authority is currently prosecuting one pleasure craft user who has breached by-laws governing in the bay.

But harbour officers have limited powers to restrict the movement of vessels on the sea, Capt Stabler admitted.

Capt Stabler said: "We aren't able to rope-off areas for swimmers like they do in the Mediterranean because in British tidal waters you have a right to navigate and manoeuvre where ever you want. All we can do is impose speed limits and warn people about the dangers."

As well as increasing his patrol hours from tomorrow Capt Stabler is issuing a revamped Notice to Mariners.

The notices are issued by harbour authorities and councils and provide navigational and safety information to users of small craft.

The new notice reminds vessels with unguarded propellers that they are prohibited within 400m of the shore between the pier bandstand and Bowleaze Cove.

It now prohibits anchoring within the 400m limit zone, except for a specified area at Overcombe marked by blue buoys. Previously, vessels could anchor anywhere along the beach.

The restrictions, in the form of a council bylaw, are for daylight hours only, and permit craft to moor closer to the beach for fireworks and other events after sunset.

The harbour authority is also printing thousands of reminder leaflets for distribution to sports and sailing clubs.

From tomorrow patrol boats in Weymouth Bay will operate from 8am-8pm instead of 11am-7pm.

The increased hours will last until the first or second week in September or later if good weather continues.