Good response, except for the last sentence. Peter, you are very set in your ways on many of these subjects and I respect you for that, but sometimes I feel you forget that not everyone is as experienced or laid back on some matters as you are. You have given ample advise on this forum that many, including myself, have absorbed to do better in the fight for our 2a rights. I, personally, strive to follow the law as it is written when it comes to this stuff and I want to know everything about the law right up to the border where something becomes illegal.
I believe this question is valid even though on the OC board because why just slap someone away if something isnt only "OC"? CC pertains to most of the same laws and regs. that we have to follow with OC.
But I digress. firearm responsibility does not strike me as silly. I take it very seriously and do not hesitate to give someone a pop on the back of the head when they do something wrong, as I expect someone to do the same to me. I mean, how else can we learn?
As for the bag... I would feel that leaving my FIREARM (not "weapon") in a bag on a populated beach is a bad idea...just like leaving it in the car. However, If you have it under constant supervision, I think it would be the same as leaving it in your car, as far as the law goes (IANAL). Since the firearm is in your bag, not on your friend's back, sitting on the beach... it is still in your property, thus should not be considered in your friend's possession. Like Peter said, put your wallet in the bag to prove ownership,
Now, if your buddy were carrying it down the boardwalk while you took a dip, then he would be in possession of a concealed firearm and would need to be a "chipper".
again IANAL.....