For a single day trip:
Tennis shoes or sandals that will stay on your feet and can get wet.
Fleece top for under your splash jacket
swim trunks or suits
sunscreen
baseball cap or visor
NO COTTON(once wet it will keep you cold)
On multi-day trips:
In addition to the above list:
change of shoes for camp
headlamp or flashlight
warm jacket and pants (it can be chilly in the mornings)
rain jacket
your usual personal care items and normal camping attire