The usual, I try to keep it to a minimum.
I had a vinyl folding business card holder, 2 pockets. When beach diving I'd slip my driver's license in the clear pocket, a $20 and laminated medical insurance card. ID if the unthinkable happened but if I drifted up or down the coast a ways I could drop into the pier at one end or a snack shack at the other and buy a munchy and beer for the hike back.
I had a vinyl folding business card holder, 2 pockets. When beach diving I'd slip my driver's license in the clear pocket, a $20 and laminated medical insurance card. ID if the unthinkable happened but if I drifted up or down the coast a ways I could drop into the pier at one end or a snack shack at the other and buy a munchy and beer for the hike back.