a.k.a. "How to Get the Title: Salty"
You get the title Salty by finishing all the achievements needed for the Accomplished Angler Achievement.
Here's a brief guide on how to get them all and the title Salty!
Word of warning: Getting the title Salty is not for you if you don't have the patience for it. If fishing is just boring to you, just don't do this :)
Fish Don't Leave Footprints
Try to get before / while doing the other achievement requiring fishing from pools (as this make's finding them very easy)
Acquire the Fish Tracking ability. You need to get a Weather-Beaten Journal, and you can get it out of many fished trunks and crates, you can also get it from the daily quest.
Fish 10 nodes in Northrend
(copied from Wowhead, credit to Ithinarine)
* Borean Man O' War School - Borean Tundra (coast).
* Deep Sea Monsterbelly School - Borean Tundra, Dragoblight, Howling Fjord (around Icebergs in the Frozen Sea).
* Dragonfin Angelfish School - Dragonblight (Lake Indu'le).
* Fangtooth Herring School - Howling Fjord (rivers and lakes, not coast).
* Glacial Salmon School - Grizzly Hills (rivers and lakes, not coast).
* Glassfin Minnow School - Crystalsong Forest.
* Imperial Manta Ray School - Northrend (general Northrend fish, found off any coast, not in lakes or rivers).
* Moonglow Cuttlefish School - Borean Tundra, Dragonblight, Howling Fjord (around Icebergs in the Frozen Sea).
* Musselback Sculpin School - Borean Tundra (Lake Kum'uya).
* Nettlefish School - Sholazar Basin (rivers and lakes, not coast)
Master Angler of Stranglethorn
Some say this is the hardest achievement as you have to compete for it and only one can get it each week. some even say it should be removed from Accomplished Angler achievement, and thus, remove it from requirements of Title Salty.
I say, you can't call yourself serious fisherman if you don't try and win the extravaganza. So go and practise, you will get it eventually. If you don't, perhaps Salty is not the title for you.
Best source for tips on Winning the Extravanza can be found from El's Fishing forums: Stranglethorn Extravaganza.
The One That Didn't Get Away
This might take a lot of work. I did this in Shadowglen (the Night Elf starting area, it took me 3 hours of continuous fishing, your milage may wary)
or more accurately, Mr. Pinchy's Magical Crawdad Box, as catching Mr.Pinchy is not enough, you must get lucky with the 3 wishes and get the mini-pet (I needed 2 Mr.Pinchies to get mine).
Empty out all the Highland Mixed Schools in the area. This means the lake by the alliance town, the lake by the horde town, and the bigger lake up in Skettis. 3-5 nodes in both the Horde and Alliance rivers, and 7-10 in the Skettis area. They spawn rather slow, so after cleaning out the nodes I would find something else to do for 2 hours then come back.
Make sure you pay attention while fishing, because he is BoP, so you need to click accept.
While at it do the daily fishing quest in Terrokar, for great rare gifts like the hat, or mini crokolisk pet.
Info from El's fishing forums
Enter the instance, go down the steps and head straight left avoiding mobs to the waterfall. Mount jump into the lake below, pop water walking and follow the river around collecting the mudskunks from their pools. If you haven't completed the lure quest follow the river all the way around to the NE side where you'll see a tent and a bunch of booze. There's a chest there with the quest item. This is also the location you use to summon the boss.
After doing the background quest and getting a mudskunk lure from Nat Pagle in Dustwallow Marsh:
Head into ZG again and water walk to the Zulian Mudfish pools and fish 5 up (bring a few water walking pots with you--if you can't solo the groups of alligator's that is--because the fish that live there will attack you from time to time (make sure you can solo a level 60 elite fish) and take off the water walking buff. After obtaining the 5 fish, water walk to Pagle's Point (just keep following the river north) and apply the lure (you don't have to cast or even have your pole equipped to do this) and congratulations! ... you are now 1 step closer to the Salty title!
This was very doable on level 70, but at level 80 this is super easy mode (mobs barely aggro to you). D note that the achievement only goes to the fisherman who actually fished him up.
Might as well bring other level 80's with you (healer, tank, dps) and try to get the Polymorph book + Tiger & Raptor bosses for the rare drop mounts.
(credit to jamras on thottbot)
Steam Pump Flotsam: Zangarmarsh, all over the lakes
Schooner Wreckage: Southshore, near dock and along coast line
Floating Wreckage: Tanaris, coast
Bloodsail Wreckage: STV, coast south of Grom'Gol
Waterlogged Wreckage: STV, Lake Nazferiti and along river
The Coin Master
This is accomplished by fishing the entire collection of coins out of the tiny fountain in Dalaran. Pretty simple, but requires patience (like a lot of these fishing achievements), so just fish, fish, fish from the fountain. Throw the gold coins back to gain the "lucky" buff, whenever you have gold coin and do not already have the buff. And do fish for the whole 2 minutes of the buff, take your break afterwards :)
(credit to Tadzulempke on Wowhead)
Brackish Mixed School - Terokkar Forest/Zangarmarsh
Bluefish School - Nagrand
Mudfish School - Nagrand
School of Darter - Terokkar Forest
Highland Mixed School - Terokkar Forest (only reachable with flying mounts)
Sporefish School - Zangarmarsh
Old Man Barlowned
There is a daily fishing quest in Terrokar. Each day the fishing quest is randomly chooses one of five fishing quests for you to do. Keep doing this quest every day and eventually you will get all 5.
The Lurker Above
Fish up the Lurker Below in Serpentshrine Cavern
This is definitely soloable, watch my video on how to do it: WoW Achievements: Lurker Above.
Catch 1000 Fish
You will get this while doing everything else on the list, don't worry about it.
The Old Gnome and the Sea
Successfully fish from a school = Fishing achievement which will come automatically by doing other achievements.
Some fishing achievements, like I smell a Giant Rat, Old Ironjaw or Old Crafty ARE NOT PART of the Accomplished Angler achievement, and are not needed for title Salty.
You might also want to look at El's compilation on Fishing Achivements
Original Brief Overview on Getting Salty by Laizhensil at El's Fishing forums
a.k.a. "How to Get the Title: Salty"