I recently bought a deal from Travelzoo (really, I never do anything at full price these days ... ) for a kayaking tour of La Jolla Sea Caves. We first met at the tour office (the deal was for OEX Dive & Kayak) and walked to the beach with the guide. Almost everyone got a tandem kayak.
The kayaking is very safe, but the time where you are most likely to flip over is when you first get on the kayak and take off from the beach. Especially for tandem kayaks, since both of you are trying to get on while maintaining balance and the waves are rougher near the shore. Yes, we flipped over! But that was the first and last time we flipped.
The tour takes about an hour - it's quite a workout for my arms! It was the first time I was in the back and it was my friend's first kayaking experience, so I had to figure out how to give directions :P
The tour guide gave a lot of tidbits about the houses we see on the shore. That white house with the slanted roof below was Dr. Seuss' house!
For the kayaking tour, I was rather disappointed that we didn't get closer to the sea caves. There were people who were swimming through one of the caves but I think for that you're supposed to buy the kayak and snorkel tour combo. I didn't know! For the kayak tour, we just kayak alongside the caves and turned back. Still, it was a nice view and a good workout.