Spring kayak season starts the moment water temperatures become survivable and air temperatures become pleasant. In most of the US, that window opens between late March and mid-April. Here is what goes in the dry bag.
Non-negotiable
PFD (life jacket). Always. No exceptions. Even calm water.
Polarized sunglasses with a retainer strap. You are on water. Glare is constant. Polarized lenses cut it. A retainer strap keeps them on your face when you paddle through rough patches or flip. Losing sunglasses to a river is a tradition nobody wants to continue.
Sunscreen, SPF 50, water-resistant. Water reflects UV back at you. You are getting hit from above and below. Apply before launching, reapply every 90 minutes.
Water bottle, clipped to the kayak. Dehydration on water sneaks up because the breeze keeps you cool. Drink before you feel thirsty.
Dry bag for electronics. Phone, keys, wallet. One bag, sealed properly, clipped inside the cockpit. Do not assume your pockets are waterproof. They are not.
Smart additions
Neoprene gloves if water is still cold. Your hands are in the water constantly and cold fingers lose grip strength fast.
A hat with a chin strap. Brimmed hats blow off on water. A chin strap solves this permanently.
A whistle. Attached to your PFD. Required by law in many states. Useful if you need to signal someone on shore.
Skip
A waterproof camera unless you are serious about photography. Your phone in a dry bag handles casual shots fine.
Excessive snacks. A two to three hour paddle does not require a picnic. One bar and water is enough.
Cotton clothing. It absorbs water, stays wet, and gets cold. Wear synthetic or quick-dry fabrics.
The eyewear detail
Cheap sunglasses are a bad idea on water. If they are not polarized, you are squinting the entire time. If they do not fit securely, they end up at the bottom of the river. Invest in a quality pair with polarized lenses and add a $5 retainer strap. That combination outperforms everything else you can bring.
Paddle smart. Pack light. Protect your eyes. The river does the rest.