According to my Coast Guard source, the SOLAS tape is the best thing to put on a small craft. Accept no imitations. "Put that stuff all over the place. Put it on you and put it all over your boat". Well, I've put it in places on my boat without going tape crazy. I bought another couple of feet last week. I hope the flares also help.

SOLAS is highly visible and reflective in daylight or by artificial light (searchlight). It's expensive but worth it. I hope I never have to test it.