Eorzea Database

Caught all 3 of them in a row with patience 2 and live shrimp, on the first cast in the little cave at shoal rock, at 10am. gathering 721 and Perception 611

Make sure you head North of NPC to Shoal Rock. Once there I used Patience 1 and Precision Hookset...only real difference I see is I used Live Shrimp as bait and it took me less then 10 minutes.

Versatile lure + Patience II
(33.2, 11.4)
1 x HQ 3.29pm, 1 x HQ 4.52pm, 1 x HQ 5.52pm (ET time)
1475 gathering / 1219 perception

You need 707 gather, 549 perception, using patience 1 or 2, precision hooksett and while using snagging to get haru fish. If you need to meld your fishing meld it.

Metal Spinner, everything off, Patience 2, Precision Hook, <pos> 34, 11.Hooked all 3 from 8am-8:50am EZT.

35.5, 10.0

Metal Spinner

Patience and Precision Hookset of course.

Less than 20 casts to get all 3 for quest.

This quest was made to specifically feature Patience/Patience II, and using them will save a lot of time. Make sure to turn off Snagging and I would recommend turning off Collect as well to save on inventory space (You also seem to get an insane amount of Ruby Laver if it's on).

For those still having trouble with this quest in particular prior to hitting level 70, the fish is considered a lv68 catch on this lv65 fishing quest. If a fish gets away from you, then it is definitely the Harutsuge Sprag, and it means that your gathering is too low. It is in your best interests to focus on leveling fisher through other methods and put all of your yellow gatherer scrips into a full set of Landking gear. It should allow you to bulldoze through the remaining fisher quests and set you up for 70-80 since 350 land king gear is better than unmelded level 77 vendor gear.

After 6pm, north of NPC at Shoal Rock got the notification:
Mark for the quest "Search for the Spawning Grounds" detected.
1211 Gathering 1099 Perception.

Didn't need precision or time, just needed to not be next to npc.

My gathering is 1851 and patience is 1374. Before 6pm I used a metal spinner and caught 13 in a row. As soon as 6pm hit, I didn't catch any more

Followed all the comments here, used Versatile Lure, Patience and Precision Hookset. My problem was that I didn't move away from the NPC at first, thankfully I read these comments and went to Shoal Rock. If you're doing the 65 FSH quest you will get "Mark for the quest 'Search for the Spawning Grounds' detected" message if you're in the right place.

caught it during clear sky and thunder, Patience and precision hookset. It took me around 30 min

Ruby Sea (35,9)
Clear Skies. I don't believe time of day matters.
Caught with Versatile Lure, Patience, and Precision Hookset. I had Snagging off. Took me approx. 15 casts to catch the three HQ. Make sure you're at least casting near Shoal Rock. I made the mistake of casting near the NPC Reyna.

Shoal Rock (Ruby Sea X32 Y11)
Caught all of mine during the day with versatile lure, patience + precision hookset.

Got 3 HQ of these at The Ruby Sea (X:35.0 Y:8.1), don't forget to turn on Patience and use Precision Hookset. Doesn't appear to have a time preference. Used Live Shrimp as bait.

No quest, I have every gathering and crafting job to 80, has ever beat me like this one. I Level 424, Gathering 1682, Perception 1370. I am on day 8, tomorrow if I try again will be 9, and I have caught exactly zero of these non HQ or otherwise. So very frustrating.

Thunder.

The Rock. 6am/6pm, you got 1 hour. Versatile Lure. Patience 2. Chum. Precisions Hook-Set. Slap all dem Grinning Anchovies.

X 32.3 Y 8.9 inside the rock
Bait : Versatile lure works
Caught mine late at night using patience 2 + Precision hookset and about 15 casts total to get all 3 hq's for quest

Tried for 10-20 cast before 6pm didnt catch any HQ and only 1 Haru NQ.

As soon as 6pm came around I caught 2 in a row.

Patience 1 + Precision hook

Gathering 529
Perception 467

Item required for level 65 FSH quest "Search for the Spawning Grounds." Quest requires 3 HQ. Not a hard catch.
Location: Shoal Rock (X:32.4 Y:9.1, the small pond inside the rock), pole fishing
Bait: Live Shrimp, can purchase from the vendor at Tamamizu (X:27, Y:17)
Time (of my catches): 3PM - 7PM (can be caught all day)
Weather (of my catches): Clear (can be caught in all weathers)
Tug: Small, longer than average wait time
Abilities used: Patience 2 + Precision Hookset. No snagging. Also caught one with a plain cast and hook.
Stats: 767 gathering, 621 perception (melded ironworks gear)
BONUS: have your collector's glove on while trying to catch these, you may also get some collectible Butterfly Fish.

Caught for fishing quest. Found at Shoal Rock.
Used Patience I with Precision Hookset and was able to catch it just fine. I hear you get more nibbles after sundown (that's when I caught them all). Gathering 613 Perception 499