added on may 2020
What
Donna said above
Also, for trophy Blue Marline at Ramsay Bay Resort, Titanium rod set, with Clams works, too. Clayfish, and Lobster work also but they catch few more other fish than using Clams. Chopped Worms chum optional. It did not speed up the completion for me (I caught 10 trophy Blue Marline each hour with or without using the chum, but with the chum the fish I caught were generally larger, and with chum I caught more overall number of fish -- mix of Blue and Black Marlins, and one other fish)
For Black Marline at Diving site, use Bass Boilies on 2000 kg set. With Bass boilies you catch ONLY Black Marlins. You can finish this part of quest very quickly. I used 100 ~ 125 Bass boilies to catch 35 trophy Black Marlins, without using Luck potion. With Luck potion this task will be done even faster.
Use of Chopped worms chum is optional if using Bass boilies. In fact I caught 7 consecutive trophy Black Marlins AFTER my Chopped worms chum run out.
If not using Bass boilies (or some other boilies) then recommend to use Chopped Worms chum since without the chum it catches many other fish also.
Using Luck potion can speed up the completion, but it is not a must.
If spin is preferred then Spinner lure works. tho it ma take more time to complete with the spin fishing.
thanks everyone for sharing!
