I have always warm weather traveled in the kayak and exit by bracing in shallow water a bit away from the rocks and making a regular exit into the water. Now I am considering a early spring trip and seeking tips on exiting in cold water. If I truly wet foot it as I do in the summer, what boots might give protection to just below the knee and yet be comfortable in the boat.

Thanks.

Not boots, but you might want to consider Sealskinz socks as an option. I've found that I don't like using them for a very full day and lots of walking or portaging, but for anything above ankle deep water in cooler weather, they're awesome. I use them most of the time when winter paddling.

Chotas are good. They no longer make the boot bottom versions so portaging may be tougher on the feet.

These might be what your looking for.
NRS Boundary shoe