Definition: A movement and propulsion technique used by cave divers to avoid silting. Involves bending the knees at a 90-degree angle toward the belly, making a circular motion with the feet and returning to the starting position.
“From this point onwards, remember to use frog kick to reduce siltation.”
Source: http://www.swiss-cave-diving.ch/Lexica/BasicCaveDivingTerms_London.html