Organisers of a volunteer rescue service patrolling part of the Suffolk coast say the number of people the crew has helped this year has more than doubled.

John Cresswell, chairman of the Felixstowe Volunteer Coast Patrol and Rescue Service, described the 120% rise as worrying and said 2013 had been the team’s second busiest season in its 16 years of service to the resort.

Incidents included rescuing four young swimmers in difficulties in the River Orwell, towing three 40ft containers which fell off a ship to safety away from the shipping lane at the Port of Felixstowe, and being called out by police to a micro-light flying under the Orwell Bridge.

Mr Cresswell said: “Probably our most dramatic rescue occurred in September during a severe gale nine, winds gusting [at] 60mph with rain squalls and heavy seas.

“On her last patrol of the day, our craft Volunteer was tasked by the Coastguard to an unconfirmed report by a vigilant member of the public ashore seeing in fading light and rain, a yacht aground in the Walton Channel and being overwhelmed by large waves.

“No radio contact had been made or a request for help been received by the Coastguard at this time.

“We were on scene in 12 minutes and found a 23ft sloop aground and being rolled over onto her beam every time she was hit by a large wave.

“Her engine was running with her propeller out of the water, making Volunteer’s approach very difficult.”

It took three attempts before Volunteer could get close enough and a rope aboard. The sloop was eventually towed into Titchmarshe Marina in Essex.

The long, hot summer had made it perfect weather for people to enjoy getting out onto the sea and the area’s rivers in a variety of craft, with those afloat including windsurfers, kite-surfers, canoeists, and people in inflatables and small boats, he said.

However, not all of them had behaved sensibly or been wearing proper clothing or carrying essential kit.

Mr Cresswell said: “Unfortunately, our casualty figures have doubled this year from 20 casualties involving 37 persons to 48 casualties involving 83 persons.” In very serious situations, at least two lives were saved.

Routine incident rates remained the same as 2012 – 59 events attended, but with 97 people involved compared with 44 the previous spring and summer.

He said: “This gives us a total of 180 persons assisted during 2013, giving an increase of 120%.”

The crew spent 54 days afloat and covered more than 4,000 miles in patrols, being tasked to attend incidents by Thames Coastguard on 25 occasions.