What does SW SCW mean in the US Navy?

SW stands for Steel Workers -- it is a rating designation within the Navy Seabees.

SCW stands for Seabee Combat Warfare -- it is a special qualification given to members of the Seabees upon completion of certain training and testing.

SCWS stands for Seabee Combat Warfare Specialist -- is a military qualification badge or pin similar to air combat "wings" or submariner's "dolphin's." It is also referred to as the SCW pin.