The cine films are now in South East Film and Video Archive.
The soundless black-and-white film, recorded on fragile 9.5mm stock on one of the first home movie cameras, captures the excitement of one of the boys, sticking his head out of the train window, grinning, pipe in mouth as he heads for the coast.
The friends smile and pose for the camera. At the beach they lie flat on the surfboard, and attempt to ride the waves standing, often falling and splashing back into the sea. It is thought to be the first time surfers standing up was recorded in Britain.
In the film Mr Rochlin, who died at the age of 96, shares his memories of surfing. "We swam out and when the waves came in, my friend Lewis tried to stand on the board, like they did in Australia. After a lot of practice we managed to do it. It was incredible. It really brings back memories. It was really thrilling, to be able to stand on the board and go on to the beach."
Barbara Steinberg, Mr Rochlin's great-niece, said she remembered him and Mr Rosenberg, whom she called Uncle Lew, talking about their holidays in Cornwall.
"They were great friends when they were young; they came from very poor families so they had to be quite creative about their holidays. Uncle Harry told me about their trips to Cornwall, they went camping there, went roller-skating and cycling. They even made their own tents. He mentioned surfing too, but I never realised that was unusual. They were ahead of their time.
"They would buy their food from farmers and he mentioned that they would tell the farmer they were Jewish when he tried to sell them meat, they only bought milk produce or vegetables."
Ms Steinberg, who works for the JNF, said Mr Rochlin and his wife Hettie had no children, and eventually moved from the East End to Brighton.
She said: "They were closely involved in the community, Brighton and Hove Reform Synagogue. Harry sang in the choir. He and Hettie were very, very pro-Israel, visiting regularly and both were on charity committees that raised money for Israel. When Auntie Hettie died, he moved to Cardiff's Penylan House to live with his sister, Bessie."
