User blog comment:ErrorZip/Preps for hardmode?/@comment-4742863-20120110182911/@comment-4736356-20120111235046

Sorry, not fin, I meant flipper. They are in random chests, and I guess that many worlds have a chest at the far end of one of their oceans that contains a flipper so that you can actually swim. Alternatively, you could use water walking potions and combine that with the obsidian skin to walk on lava. I'm guessing you've found a few of those. Once you got the bridge built, it won't be an issue. With the bridge, the phoenix blaster, and your molten armor, the Wall of Flesh will be a piece of cake. I fought him under identical circumstances and it was probably the easiest boss fight I had done yet. Haven't done anything in hardmode yet, but it took me like 2 minutes to realize that it earned the name "hard mode" for a reason.