First, take off your pants
okay now I'll tell you--
seriously--qucik sand is mud or sludge, frequently around or over comoflets--so, first don't panic, slow your breathing and keep your lungs as full as possible--don't struggle. You cand swim in mud, but you have to have less up pressure than down. Try to get horizontal to the surface----look for something to grap onto--and take off your pants tie knots in the legs inflate and hold on---or just call 911 on the cell