Warlords of Atlantis (aka Warlords of the Deep, though see below for further variant titles) is a 1978 British adventure science fiction film directed by Kevin Connor and starring Doug McClure, Peter Gilmore, Shane Rimmer, and Lea Brodie.

The plot concerns a trip to the lost world of Atlantis. The screenplay was by Brian Hayles.

https://en.wikipedia.org/wiki/Warlords_of_Atlantis