RE:The 4 subtanks

The first 1 is in underground forest, when the two gyrator are. Destroy the second, and
fly up, there's a subtank.
Two other subtanks are to trade by the fourth reploid with two S-Crystals.
The last 1 is in the IceLevel, there you have to go at the beginning up, and when theres
the "Hole" you have to jump down and go trough the door. Then grab with the Z-Knuckle the
chip from the crab. Then go to the door with the electric grills and attack with the chip,
in the room theres the last one.