Does not tend to absorb biologicals.
Does not absorb water, mud, feces, odors.
Outstanding strength
Very low maintenance
Great handling characteristics... even when wet
If it gets wet, Simply wipe with a cloth and it's dry (ideal for those water searches!)
When it gets dirty, wash it with soap and water.
Can be disinfected
Flexible in cold weather
Washable
Sealable

You might want to consider a waist-leash. It is made to fit your waist (plus 4-5 inches) and it has a ring in the handle. When your dog is working off-lead, you clip it around your waist, like a belt. When you need to put your dog back on-lead, it is always handy. No fumbling around and wondering "Where did I put my leash?"

Waist-leash: