There's 4 floating rocks in Aanthirin right outside Hlan Oek, 3 clumped together and 1 nearby.

For some reason I couldn't upload screenshots, so I can only provide the plain text info:

• All in cell Aanthirin (3, -32)
• T_Mw_TerrRockAI_Rock_01 (solo one) and _14, _15, _16 (group)

Found in Lake Andaram section 0098

EDIT: nvm, apparently I can, even if it throws up an error. So screenshots attached.

EDIT2: limit of 3 screenshots, but you can see the fourth rock, shouldn't be an issue to find.