Some of the fast, young surfskiers in Bellingham, WA. paddle almost year around barefoot. Chances are you will want a little more protection for the bottom of your feet and/or for warmth in cold weather/water.
Always a good idea to rinse with fresh water and dry all of your water gear between uses. If you forgot to dry your gloves and booties after the last outing you may be able to dry and warm them a worthwhile amount while driving to your next session if you can prop such items close to heating vents in your car. Air dryers for boots and gloves are relatively inexpensive - but given their low cost, don't assume that they are immune to overheating or becoming a fire hazard even if they supposedly have auto shut off safe guards. Only use dryers on stable surfaces that are well away from any flammables.
Many of the wetsuit manufacturers sell their own booties. Below is just a sampler. You will have to try some and decide which style and thickness suits you best. As mentioned in a discussion above, pay particular attention to how much room you have within your surfski footstraps and foot pedal area - this may affect your decision on bootie thickness and/or how thick/heavy duty of a sole you want or are able to use.
Cheap ones are not very waterproof and most will not retain waterproofness very long. The better ones (typically more expensive) will last somewhat longer particularly if they are well taken care off: No long toenails, or else thin inner socks are worn to protect them and some kind of protection is used on their outside as well - paddle shoes or water slippers that will fit over them. They also generally do not have much of a seal at their top, so water can flush in much faster than is typical with booties.A couple of the better makes: Sealskinz, Dexshell