If it's a floater, you might not like what you find. Assuming it is found. I'll be interning in Monterey for the next two days; I'll keep my eyes and ears open.
I'm not sure what you're reasoning was for attaching a float to the GoPro. Personally I've found this method of lost-recovery to be worse than an item that sinks. And believe me, I've lost quite a few GoPro sized collection vials in my scientific diving career; some floating, some sinking (depending if I remember to flood it or not prior to diving).
If you lose your item in deep water, it floats to the top away from the boat. You're not going to be able get the boat to chase after it once you surface (until all divers get back on board). That's assuming someone spots it.
In shallow water, there's more of a chance for you to safely extend your dive time to search for it. You can even do another dive if it means that much to you. On the surface you have to possibly battle surf, waves, white caps, and the landscape. The item has a better chance to be mobile on the surface than on the ground. Meaning it can reappear in a spot you've already looked at, while you're looking elsewhere.
I think the odds are much better to find your gear underwater rather than trying to recover it after it has detached and surfaced away from you.
Just some food for thought.