Stuck trying to get a ? (Silenta Meadow - East)

[Naozie]

There is a ? in the water near a rock (Silenta Meadow - East)
and I have no idea how to get it

[Morghen]

Pretty sure it should a breakable rock. I'm not that far into the game to be able to tell you more but it seems certain bullet can break walls and other things so... progress a bit more and you'll maybe have your answer :D

[Naozie]

yea you can use the burst bullets to destroy it but for some reason i did not test it

[Danierru]

a bit late here, but you have to complete pioneering quest 100% on Ligneus region first to simple synthesis Burst ammo and then shoot the rock with the burst ammo