My cousin's in a specialist plod unit, all sneaky beaky stuff and that. Last time I saw him he was wearing Oakley SI assault boots, very light but not very waterproof.
He said they were the dogs b*llocks but then he is only a plod.
Magnum Phantom 8" V-lights if you can find them. The PX has them for around US$70.
Apparently designed for 'Para Military/police/SWAT' type activities.
No metal parts, very very light. Robust, waterproof, very comfortable etc etc. If you can find the ones without a zip, then even better.