Lots of Lunkers

Found the answer to this achievement by mistake.
Was fishing really close to a "Large Lunker Sighting" in the Waking Shores (way 65.66, 74.10).

Using my fishing cast and only upon looting a random [item=194701], it would automatically cast a "Looking for Lunkers" spell after looting the conch.

Be careful to not move or recast immediately your Fishing spell or it WILL interrupt the "Looking for Lunkers" spell. Note that the spell seems to be 11 seconds long but it will actually proc the lunker before the end of the cast.

Only when you let the automatical cast proc the lunker will you earn a point towards achievement.

As stated in other comments, pulling lunkers with harpoon during the weekly fishing worldquests IS NOT the way to progress on this achievement.

PS : Note my fishing skill was 100 and my Tuskarr rep was lvl 13. But I think you actually only need to posess a Iskaaran Harpoon.
PS2 : Note that using 5 [item=194701] at a "Large Lunker Sighting" will also grand a point towards this achievement, but that is a way harder way to do it.

This achievement only counts:

1. 
   
2. Lunkers that you personally summon by using 5x [item=194701]
3. 
   
4. Lunkers that you personally summon from [spell=392270], the buff you receive when you loot an Ominous Conch
5. 
   

It does not count:

• 
  
• Lunkers summoned by others
• 
  
• Lunkers summoned or harpooned by party members
• 
  

If you're wondering what the difference is between We're Going to Need a Bigger Harpoon and this achievement (plus the other two in this chain): We're Going to Need a Bigger Harpoon does not count lunkers summoned from [spell=392270], only lunkers that you personally summon by using 5x [item=194701].

I'm not getting credit for any lunkers reeled in with my harpoon during the world quests. I've done probably 5-6 of the world quests but am only at four lunkers for this achievement. Anyone having a similar experience?