If Zim and Roger made it to Section F without incident, he would re-engage Black Star's Thermal Scythe. The armor plates would still be in the down position to try and protect against an ambush. They were attempting to take down up to five units with just the two of them. Zim still had no idea if Black Star would survive a splash, or if the opposition werks would be either. Going from the open plains to the beaches around the lake would go from no cover, to no cover with poor traction with shifting sands. Zim would have to attempt to do something that he had practice many times and had little success in training. He would need to use his thrusters to blitz the enemy. 

'Please Black Star,' Zim begged his machine, 'I know we can do this. Come on, lets pull this off!'

Once the opponents started opening fire, assuming that they were using ranged weapons, Zim would use standard evasive maneuvers to try and close the gap between him and the nearest opponent. He would hope that Roger could provide cover-fire while strafing to prevent himself from being a sitting duck, and that he would recognize the melee nature of Black Star and pick a different target. Once he got close enough for a straight line boost Zero would crouch Black Star down, open his armored wings, Scythe drawn back for a full swing, and push full throttle to his jump boosters with the intent of that launching him directly into the target. With any luck, Zero and Black Star would work together in this attempt and the timing would work out for Zim to use the Scythe to cut the opposing Werk in Half. If he didn't, then he could only hope that Black Star would slam into the werk and shove it bodily into the depths of the water, hoping that the damage itself would be enough to incapacitate the foe, or that the depths below would finish the job. 

If able, he would close his armored wings and assess his next attack, if there was time, or simply act reflexively... If Black Star allowed.