We rented SUPs at Kayak Connection, which was a great shop located right by the bridge that runs over the Marina on Murray Street. There was paid parking between the shop and the docks, as well as free street parking. We found a spot right in front of the shop.
After renting boards, and putting on wetsuits (provided by the shop) we walked down to the shop's dock which is about a quarter mile away. The dock is locked, so you'd need to find another place to launch if you want to use your own board.
Since it was Thursday morning, there wasn't much boat traffic in the marina but there were lots of seals and sea lions. We paddled away from the ocean to the end of the marina, then turned around and paddled back.
The Santa Cruz lighthouse is on your right where the marina joins the open ocean. The waves are breaking so you need to stay left as you paddle out. It can be a little hairy but once you pass the lighthouse the waves calm a little bit, but you will still feel the swell of the open ocean and you can see the whole bay and the Boardwalk. We had to go down on our knees and were thankful for our farmer john wetsuits.
Ann and I were a little intimidated by the open water (sharks!) especially when we saw fins. But they turned out to be a pod of eight dolphins that swam across the bay about 100 feet away.
My takeaway about Santa Cruz - the marina itself is kind of boring. The open ocean is wonderful if the weather is calm and you are not afriad.
Unfortunately I pressed the wrong button on my camera and all of my dolphin photos came out in black and white.