Yes, I had an assigned buddy in adive club flash me the 500psi sign at 90 feet. I switched my regulator for my air source regulator (making it my new primary) and held the now open original primary out to him and then pointed towards the surface. We made our first safety stop and on the way to the second he took the available primary and we ascended to our second safety stop, completed it and then surfaced. 400psi remaining on my tank, we orally inflated our BCs and headed to shore.