Vana'diel Bestiary: Beach Monk  

Inside the Belly mini quest. First obtain a Pirate's Chart by turning in Bhelfel Marlins to Zaldon. Once in hand take the Chart to Valkrum Dunes(Whitebone Beach).

You will need 2 friends(have them bring fishing poles and some bait). Make sure you all have 20 lvl gear. Best party setup ive seen is brd,blm,pld. Trade the chart to the ??? and you will get a semi cutscene. As soon as you can start fishing. You will only pull up Snare's(Mithra and Tarutaru). Taru snare weakens the mobs attacks and Mithra paralyzes it(I think, never used mithra one before).

You will only have a few seconds to fish these up before the mobs appear(Sahgin, Crab, Manta).
Have blm sleep the crab, bard sleep the Manta, and pld engage the Sahgin. Hopefully everyone has a snare from fishing from the start. All 3 mobs will use Hundred Fist about half life(Maybe a little less). Once he does have the paly use the first snare on the Sahgin. Will make him extremly weak or paralyze it so it cant hit as much. Once Sahgin is dead have pld pick the next mob, and make the bard take over/keep sleeping the 3rd one(No mp loss). Blm can support on the second mob. Once it uses Hundred fist have the blm use his/her snare on the second mob. Once dead all kill the last one and then let bard use his snare on the last one.

After they are all dead a Treasure chest will appear. Open the chest a reap your rewards.

I've recieved:

Albatross Ring
Tiny Pugils(x2)
Fuscina
Rusty Subligar

You can recieve some other great stuff like Mercurial Kris(Someday><).