I don't know anyone who wears a life vest when practicing instrument approaches into Watsonville (but then, I don't know everyone).
I actually bought lifejackets for flying the ILS into Monterey, which involves a long over-water approach with no hope of gliding to terra firma.
There is no way you can get a Class B entry through the airliner approach paths between the West bay and the East bay
I'm sure that's true - I've never tried - but there are lots of places you CAN fly under the Class B or where they will let you in if there's a good reason. I must have flown the "Bay Tour" of one kind or another nearly 100 times, and have only been refused Class B or politely sent to Oakland's Class C a handful of times. Of course a lot depends on whether you sound like you know what you're doing.