This is the terrestrial walker. Its meant to be a large-scale, non-humanoid mech.
This thing was designed by the world nations to counteract a gravitational anomaly near Earth; This huge walker traverses the planet with a man-made 'gravity-anchor', countering the effects of the anomaly and keeping Earth at equilibrium. I like the huge, blocky legs, the sort-of spider or gorilla profile and am shying away from the long-neck sketches.
This guy is meant to be an aquatic capable land/sea defense mech. I want to pull from more organic mechs (evangelion though not pictured). I like the ability of rapid, fluid, human movement. I've referenced some old-school japanese robots (see thumbs up jet jaguar) and think this guy should be ultra sleek, though it may not be conveyed as such in these sketches.