Green’s Dictionary of Slang

blimp n.²

a glance, a look; also as v., to glance.

1965		L. Dunne Goodbye to The Hill (1966) 120: They’re blimping your crotch to see if you’re bulging a bit.
1975		A. Bleasdale Scully 98: A few quick blimps at dirty postcards down in the bogs.
1999		N. Cohn Yes We have No 201: Just take a blimp at Blair’s teeth.
2000		J.J. Connolly Layer Cake 80: She was sending over blimps, you know.

In phrases

on the blimp

wandering aimlessly around, looking around.

1982

P. Redmond Tucker and Co 99: Let’s go down the precinct on the blimp then.