In addition to the required whistle attached to my PFD, I keep an expired driver’s license in one pocket. In the other pocket is an Ocean Signal PLB and a small wedge of a cut-up compact disc is tethered to a pocket for a signaling device.
At a symposium I attended we were handed small white cards and told to write the name and phone number of our contact person. The cards were collected, laminated and returned. Wasn’t very confidence inspiring at the time, to have to write your contact info in case of death or injury before the first classes went out but in retrospect it’s a good idea. It’s stashed next to my driver’s license.
Water and a couple protein bars are always carried.
When I’m not paddling at home, the following are always carried:
Two small dry bags which contain extra sunglasses, a pair of reading glasses, first aid kit, Leatherman multi-tool, emergency blanket, gloves, a roll of Gorilla tape, paracord, waterproof flashlight, bug net, bug spray, a few sheets of paper towels and a small pack of hand wipes.
iPhone in a waterproof bag.
Each of my boats carries the USCG “if found” label with my name, phone numbers, etc.
First aid kit came in handy once when a cut on my hand reopened as I was paddling. Same for the Leatherman when my skeg was stuck because a small pebble was in the housing (that was before I drilled a hole in the skeg and attached a line).