Catching Horsea in Pokemon Silver?

I would really like a horsea so I could eventually have a Kingdra. I am at Whirl Islands right now and I cannot for the life of me find one. A couple places I have checked online say that I need a super rod to catch him but I wanted to see if I could get anymore input. It would be awesome if I could catch one with a good rod or if one would just attack me in one of the whirl island caves. So does anyone know if this will happen for me or do I need the super rod??