Using the Old Rod in Pokemon Ruby (or any Pokemon game for that matter) will get you a Magikarp as that is the only Pokemon an Old Rod can catch.
I think you can use a good rod not sure about the old rod super rod is the best
You can get Horsea by fishing on routes 132, 133, or 134 in Ruby. You may be able to catch it with a Good Rod but a Super Rod would be your best bet.
Super rod.
You get your first fishing rod in Dewford town and the best one in mossdeep city. :) !! cheers
magikarp.....
Super rod.
There are three types of fishing rods in Pokemon Ruby. The Good Rod is found by talking to a fisherman on Route 118.
wailmer and sharpedo
lots of things
With a fishing rod that you can obtain in Dewford.
:o i just got a super rod.......forgot where i got good rod