I fish Alaska so its a little different. having said that, I caught a nice king salmon last weekend out of the saltwater!
My two cents and keep in mind Alaska is NOT California but cold water is cold water. Waders or hipboots as a replacement for a drysuit will get you in trouble at some point, Everyone thinks its because the waders or hipboots will fill with water and you will sink. That's not true. In fact if you fall over with them, the water pressure pushes the waders up against your body and you have very little water inside. Your PFD will float you without any problems.
BUT what you will be is drenching wet, and weigh about 50 pounds more due to the water weight and if you can safely reboard your kayak with that additional weight, then I guess it's ok. I can't...or I should say I couldn't...
Second, lets say you can reboard your kayak. Then if you are able to withstand being completely drenched and go about your business with no hypothermia, then no worries again. Once again, I couldn't.
Yes, I have lived through this experience. I also watched as a buddy flipped his yak on a surf landing. Struggled a bit to get to shore but he made it. But once on shore, he was so cold and shaking he couldn't get his clothes off or access his keys. He saved himself from drowning but the chances were high that if he was alone, they would have found him dead next to his truck with his keys in his pockets.
A drysuit is expensive so I understand not wanting to do it for such limited opportunities. But just keep in mind thay call it a "dry suit" for a reason. "Dry" is important not only to stave of the hypothermia, but also to keep the water weight off of you so you can recover.
Try a re-entry with your gear....soaking wet. I am willing to bet you can't do it. But if you can, then come to shore, and see if you can get all of your clothes off and get back into your vehicle without assistance. Once again anything with water and air temps in the 40's...even 50's...I bet you have a hard time peeling of all the warm weather gear you have on that is now completely drenched. Heck if you have ever gone swimming with your clothes on in the middle of summer, you know its almost nearly impossible to get your clothes off when wet. Even a light t-shirt. Now try it with a heavy winter jacket.
If you are going to use waders, please pair them up with sealable drytop. You MUST keep dry in case you fall in to avoid the excess weight and hypothermic effects.
I absolutely DESPISE a few of the well watched videos that basically tells everyone that waders and a belt is a safe system. They are wearing a sealable dry top in the video I saw or very light watershedding clothing on top. So very misleading that he says waders and a belt is safe. Waders, belt, AND a sealable drytop? Well that's something completely different.
Not sure if this is kosher but I did write an article about my experience you can find here: hope its ok since it is about safety.http://www.kayakfishingmagazine.net/articles/139-kayak-fishing-how-to-articles/1676-qwaders-of-deathq-another-perspective.html