Although many of the 2nd Unit and underwater sequences were shot at Wakulla Springs in Florida, Julie Adams remembers that all the 1st Unit above water footage was shot on the backlot at Universal. The body of water beyond Park Lake was featured as The Black Lagoon in close-up shots featuring the Creature.

The underwater scenes, shot in Florida, featured Ricou Browning as the Creature. On the backlot, the Creature was performed by Ben Chapman, who sadly passed away February 28, 2008. As well as being scattered near his Hawaii home, his ashes were scattered in the Black Lagoon, adjacent to Park Lake.

The scenes around the camp were shot at Sierra Canyon in Chatsworth..

Various soundstages were also used in the production.

Links:

• IMDB entry