Allan said the underwater sequence following the bridge jump was her favourite scene of 2009.

The underwater sequences were filmed in two specially constructed tanks.

Weather effects and underwater sequences add to the effects.

They can call for advice in 18 areas from car crashes to wild animals and underwater sequences.

The underwater sequences - which occupy most of the film - warrant the price of admission alone.

She also added: "They even stayed underwater for three or four minutes for the big underwater sequence."

Lengthy piece of music recorded for the underwater sequence.

Since no dialogue was possible during the underwater sequences, Bridges provided voice-over narration for all the installments.

The underwater sequences took two days to film.

Griffith also appeared in a small role and directed some underwater sequences.