It had taken several hours of queueing and three visits to the station master's office at Bombay Central to secure a second-class seat on the Deccan Express to Lonavla.
Because of the torrential rain, the 6.35am train pulled out slowly, at 7.45am, on tracks just visible above the floodwater. It finally picked up speed on the outskirts of town. Every seat on the train was taken and all standing room occupied. A man selling tea from an urn moved up and down the crowded aisle and there were men selling sweets, soft drinks, snacks and clothing. A young girl, no older than five, was singing and begging for rupees.
Every weekend during the monsoon season (June to September), the middle classes leave the hot, dirty, noisy streets of Mumbai in their thousands and make the three-and-half-hour train ride to the twin hill resorts of Lonavla and Khandala 129km to the south-east. Here, 625m up in the Western Ghats, the air is cooler and pollution-free. There are dams built to supply hydro-electricity and waterfalls that only appear during the monsoon.
With shoes dangling round my neck, I waded knee-high through a rapidly-flowing mountain river. There were hundreds of people dressed in their weekend best, even though the rain was constant. By now, I was so wet I had given up on my umbrella. The cold mountain water tugged at my legs, threatening to throw me off balance.
Climbing out of the river, I followed the crowds up a well-worn path. As we got higher, make-shift food stalls appeared on either side of the track, and the sound of running water became louder. Around the next corner a crowd had gathered.
I pushed my way through to see that the path stopped abruptly. There was a two-metre drop to the waterfall - floodwater running off the Bushi Lake reservoir and down the granite steps of the overflow. I had to shout to the person next to me to make myself heard above the roar of the white water.
The waterfall was crowded like a seaside resort on Bank Holiday. People were sitting in the water, bathing fully dressed. Tea and food sellers moved up and down the waterfall, sheltering their wares from the rain under umbrellas. Ankle-deep in water, a vendor had set up a stall in the middle of the stream, selling sweetcorn cooked on a tabletop fire.
In the auto-rickshaw on the way back down the hill to get the 6.24pm Shatabti Express back to Bombay, it dawned on me why everyone on the morning train had a change of clothes with them: Lonavla has only one clothes shop. I stood self-consciously on the station platform in brown, bum-hugging slacks and an outrageous disco shirt. Bollywood here I come.
• Air India (020-7439 3627) flies daily to Bombay from Heathrow from £447 return including tax, British Airways (0345 222111) from £490 including tax.
