Swim 60 miles accross a river

A blonde, a brunet and a red head were in a competition to see who could swim 60 miles accross a river.

The brunet swims 30 miles, gets a cramp and drowns.

The red head swims accross 30 miles, gets bit by a shark and drowns.

The blonde swims 30 miles accross, says: “I’m tired.” and swims 30 miles back.