In Time Crisis II, the Frogmen wore white-black colored diving suits which have ski masks underneath their breathing helmets (the ski mask is only seen in the attract mode) and have water jets attached on their backs. Their weapon is a gauntlet on both arms.
In Time Crisis 3, the Frogmen wear blue-grey colored diving suits, equipped with water jets attached on their backs, and are armed with a gauntlet on both arms. Those in the the first stage of the "Rescue Mission" are also equipped with night vision goggles.
The Frogmen are a common enemy that fight near rivers and coastal areas. In Time Crisis II, there are 6 of them and will fight alongside with the boss in Stage 1 Area 3. They are seen diving underneath before attacking from the sides. In Time Crisis 3, they will come up, and attack in Stage 2 Area 2. In Stage 1 of the "Rescue Mission" of Time Crisis 3, Alicia Winston will come across a number of Frogmen at Marano Beach and those are equipped with night vision goggles.