Find Fish

I spent nearly half an hour looking for instructions on how to get this spell, and another half an hour trying to decode the WoWese used by the people who'd written the instructions. If you could understand everything that's already been said here, you can skip this. This post is the post I wish someone had written before I started trying to figure out how to get this spell. I apologize for its length.

A "node" represents a school of fish, some wreckage, or an otherwise-beneficial region for fishing. These zones are roughly the size of a Voidwalker. Getting your fishing bobber to land inside a node (a) radically alters the drop rates and (b) reduces the number of fish in that node. Think of them as like herbs or ore veins, except you can loot them more than once before they vanish.

While I can't prove this (I spent nearly an hour looking for reference material; maybe I just suck at finding information) it seems like there are a finite number of nodes in any given place at any given time (again, like herbs or ore veins), but whereas a vein that was Iron Ore the last time you saw it is pretty much guaranteed to be Iron Ore when it respawns, fishing nodes can come back as something else.

As a bunch of previous posters have mentioned, you'll want a Wreckage node, as it seems these have a much higher drop rate of the containers than the other nodes. The problem is, there won't necessarily be any. Other people need stuff in these Wreckage nodes too, so they tend to get fished rather fast. When the node respawns, it'll be a "school of fish" node rather than more wreckage, and this will just stay there until you come along.

So here's how I got it:
As a level 58, with 214 fishing skill (although neither of these are prerequisites; 150 fishing and high enough that the mobs in Wetlands are just a nuisance), I rode the entire length of the northern shore of Wetlands looking for a wreckage node. Naturally there weren't any. (These are blatantly obvious to the naked eye, so if you see one, you'll know. It looks like floating crates and debris.) So, I rode back the other way, this time looking for fish schools (You can see these too if you know what to look for: an expanding white circle on the surface of the water. When you're closer you'll be able to see a bunch of little fish and the text "School of (something)" when you mouse over.) and fishing them until they vanished. Finally, I rode back the other way looking for respawns. The third respawn I found was a wreckage node, and I got the Weather-Beaten Journal the second time I fished from that node. Total elapsed time: about an hour.

Edit: Did this again with my 61DK. This time I was actually farming for these journals to give them to friends. (The journals are Bind on Pickup, but the crates are not, so as long as you don't remove the journal from the crate it's transferrable). Managed to get two of them over the course of about three hours alternating between Wetlands and Southshore. Both are good sites, but which one is better seems to be pretty random.

Apart from wowhead and guessing, my source of information on this is here, which is apparently a site entirely devoted to WoW fishing.

4.0.3 edit: The drop rates for these have improved dramatically, and all the locations have changed. I got six of them in the space of an hour in Wild Shore, along the southern coast of the Cape of Stranglethorn. If you're seeing Bloodsail Sea Dogs and Elder Magi you're in the right place. Look at other posts on this page that say (Patch 4.0.3) for more locations.

I felt I should add this. You can buy the "Angler's Guide" now. At least it is in Dornogal at the fishing vender.

I think it is new to the "War Within" expansion but I am not sure. Main thing is you don't have to fish it up anymore.

Fishermen and women can now track fishing nodes. This ability is learned from a journal sometimes found in crates obtained through fishing.

When active, nodes will appear as little yellow dots on your mini-map, just like with every other tracking ability in the game.