Great topic, Steve. This is a fine example of a reasonably possible survival scenario. It doesn't always have to be "Robinson Crusoe" or a plane crash in the Andes.

Like any challenging situation, the priorities should be

1) Mindset
2) Tactics
3) Skill
4) Equipment

Mindset: "I will plan ahead, and I will survive!"
Tactics: "Swim parallel to the beach to exit the current. Notify friends that I'll be out surfing"
Skill: "Be a fit and capable swimmer. Know how to use basic signaling devices"

Some observations on Equipment:

- Buoyancy would be very desirable. Perhaps consider using a boogie board that is tethered to your ankle. Adapt your style because in a tough swimming situation, extra buoyancy would be very welcome.

- Signaling: signal mirror, bright & focused waterproof flashlight, whistle. Maybe add a small strobe. Very effective, light and small. However you carry these small items, consider keeping them tethered on dummy cords made from de-cored 550 cord or something. They would be easy to lose when you open your pocket while swimming in an emergency. Consider having a cellphone in a waterproof case.

- There are various models of drybag-style waist packs out there that you could use for a little extra gear. Here and here are some examples. You might be able to surf with one of these and not attract too much attention.

- Do you do your surfing with goggles? If not, consider toting a small pair and a noseclip to help prevent aspiration while swimming in choppy conditions.