Sonic disc

Sonic disks were sonic weapons devised by the Sea Devils during the time they ruled the Earth with the Silurians. They served as a kind of heat ray, capable of scorching ships and sinking them.

The Sea Devils used them when they awoke in 1972 and again in 2084. They also possessed a larger cutting device for cutting through doors. (DW: The Sea Devils, Warriors of the Deep)

Behind the scenes

 * The Silurians in DW: The Hungry Earth / Cold Blood were seen in pictures and trailers carrying a similar type of this weapon, but with a bigger and longer handle on them.
 * The toy release of the sea devils names it as a heat ray.