By Jayshree Bajoria BBC correspondent in Bombay

Organisers hope to have one million spectators for the races

Hundreds of thrill-seekers are gathering every day at the promenade to catch sight of these amazing machines.

On Saturday, 12 teams from across the world will compete for the six places in Sunday's Grand Prix.

The boats will career for about 45 minutes around the 1,500m course and its five left-hand turns.

The race is being sponsored partly by the government of Maharashtra, which is eager to develop Bombay's profile as one of the most favoured venues for international sport events.

Before we came lots of people warned us you will have problems in India... we faced no such difficulties Nicolo di San Germano, race organiser

State chief secretary Ajit Nimbalkar says: "This will reap long-term benefits for us. This will promote tourism and sell Mumbai internationally. People will see the famous spots of Mumbai on television when the event is broadcast live.''

Race organisers and the state government expect one million spectators for the big race and to reach another 270m households in a live television broadcast.

The event will cost about $4m.

Law and order

Race organiser Nicolo di San Germano said that it was the first time in his 13 years of sports marketing experience that a government had been able to organise such a large-scale event within five months of the first meeting.

"Before we came here lots of people warned us that you will have problems in India with customs and warned us of high costs and bad service, but we faced no such difficulties," he said.

The colour of the race will be matched by India's Holi festival

Eight-time world champion, Italian Guido Cappellini, told the BBC: "My target is to win 10 championships. So I have two still to go."

The event is bound to be colourful as it clashes with the Hindu festival of colours, Holi.

Indians celebrate Holi by throwing either dry colours or coloured water on each other.

It is a festival full of energy, music, dance and Bhang (an Indian liquor).

But it also creates law and order problems and usually the festival sees high security on the roads.

"This festival is celebrated with wild abandon," said a senior police official. "And the race will draw huge crowds. So it will put more pressure on us to maintain law and order."

Future stars

Bombay's kids are also getting in on the F1 action.

Children aged 8-14 have enjoyed the Formula One Future event

The Formula One Future programme supplies training to help them become the next world powerboat champion.

Around 75 children between the ages of 8 and 14 have been taught this week and 12 will race in a final on Saturday.

Young and enthusiastic voices scream out their reasons for loving the sport - "very fast", "pure hardcore speed", "a once in a lifetime opportunity".

A fourth enthusiast says: "When you are driving that fast, rounding the marks, not hitting them, and coming back with the best time - that's the best part."

The glitterati and journalists have also experienced the adrenalin rush on the two-seater powerboats - being driven at high speed, turning dangerously, hearing nothing but the deafening sound of the engine.

One of the sponsors, Gautam Singhania, the chairman and managing director of the Raymond Group, who loves speed and is a water sports enthusiast, says he is looking forward to a fast trip in one of the boats.

"This is good for the country. It's good for the country's image."