For Bollywood actor Zayed Khan, who is trained in scuba diving, shooting underwater scenes for his forthcoming venture "Blue" was no big deal. But he faced a real challenge when he had to swim around sharks in the thriller.

"Just the idea of swimming around with these unpredictable beasts (sharks) was difficult. We always had our trainers and divers around, " Zayed told.

"Blue", a big budget underwater action adventure shot extensively in the Bahamas and Thailand, is Anthony D'Souza's directorial debut. Being made at a whopping Rs.1.29 billion budget, the film also stars Sanjay Dutt, Akshay Kumar, Lara Dutta and Katrina Kaif.

"Blue" is said to be the first Indian film to have been extensively shot underwater with a screen time of 20-25 minutes and with real sharks, almost 40 in number.

For Zayed, shooting these action sequences was a real adventure.

"When you train as a student, you go till a maximum of 35-40 feet. But when we trained for the film, we had to dive down to 85-90 feet deep enough to get actual shots of weed and sunken ships. It was scary, " Zayed said.

But the director used adequate safety measures while filming the risky shots, says Zayed.

"We were always surrounded with safety divers and all of them used to be at a distance of not more than 10 metres while the shot was being taken. There were 20 other divers around doing something or the other, so we were secured.

"Trainers instructed us not to keep long hair and not to colour them blonde as sharks get attracted to white. Then they told us that we shouldn't have any cuts on our body and if at all we had any, we should bandage it well. So when we went down, it was always with a lot of baggage in our head, " Zayed said.

For Zayed, the real heroes were the stuntmen, who accompanied the actors under water and ensured that the shooting goes on smoothly.

"The stuntmen made it look so easy. They have a way of dealing with fear. There were times when they first made me touch the sharks and slowly got me to do the fight sequences. But it was all done very carefully, " he said.

Zayed also recollected how stuntmen used to sometimes ask him about his favourite song and he used to hear them through an apparatus fixed in his ear under the water.

"Once I told them I wanted to listen to Eminem songs. In seconds, I could hear it and I believe all the stuntmen and divers could hear it on their apparatus too because they started dancing. It was such a surreal scene. I thought I was walking on the moon, " he said.

Produced by Shree Ashtavinayak Cine Vision Ltd, "Blue" is scheduled for release next year May 29.