  Presented are toy-models for sub-luminal and super-luminal warp-drives in 3+1
dimensions. The models are constructed in a chimeric manner - as different bulk
space-times separated by thin membranes. The membranes contain
perfect-fluid-like stress-energy tensors. The Israel junction conditions relate
this stress-energy to a jump in extrinsic curvature across the brane, which in
turn manifests as apparent acceleration in the bulk space-times. The
acceleration on either side of the brane may be set individually by choice of
model parameters. The Weak Energy Condition (WEC) is shown to be satisfied
everywhere in both models. Although the branes in these toy models are not
compact, it is demonstrated that super-luminal warp-drive is possible that
satisfies the WEC. Additionally, the nature of these models provides framework
for speculation on a mechanism for transition from sub-luminal to super-luminal
warp. Neither quantum effects nor stability of the models is considered.
