Hand it to you method. Not worth the risk and the cost. This coming from personal experience....holding it in hand years ago and flooding was the result.
Think about this...the only cost to pop back up and reach over and get your rig from the dive guide is a few extra seconds. But the potential cost to rolling in or holding it while rolling or striding off the boat - $1000s and no pictures for your dive trip. And with what we spend and or time to get to some of our destinations, a few extras seconds every time is well worth it.
Just my 2 cents worth today - DiverPam