M_Boats: trailer lights

What are you skippers using for trailer lights. I now have a light bar that I take off at launch time. The problem is that it has been known to come off the trailer when hauling the boat and drag down the hwy pulled by the wires :(. Any one using LED's ? Are they waterproof? Where do you skippers get them. Capt'n James A. Sadler skipper sailing vessel Pelican M-15