Originally Posted by seayalatermoonglow
But you still need the little green pin if the handle was pulled or the yellow donut if it was submerged.  If it's a Mustang, not sure of the others.
[edit again] Not sure what I was thinking, the manual ones don't have the yellow donut, so strike that part of the sentence.
You don't need the green pin- it's just an indicator to notify you that the vest has been activated, and the cartridge is empty. You can check this almost as easily by just unscrewing the CO2 cylinder, and verifying that the tip hasn't been pierced.
Also, I think it's unlikely that my vest would get inflated, and deflated without me ever knowing/remembering it.
Another thing- I always use my manual vest with a harness. I think the harness is actually more useful, since I usually sail with inexperienced guest crew and they'd be unlikely to successfully perform a MOB recovery. AKA singlehanding with guests.