Ultimate Weapon Onion Knight

I beat the ugly fishy thingy at Baaj Temple. I just cannot find the chest for Lulu’s weapon. Where is it?

You swim down in the water, Unfortunatley, i cant remember where exactly, but just swim around, i think it may be in eastern part of the water.

Somewhere to the east on your map I believe. The camera angle will change. At this point just keep pressing X since it is out of view.

oh thank you both.=)