Just having one is better than not having one, so you can infalte it at the surface to make yourself more visible. But....how much is your life worth? Get one that has an overinflate valve so that if you deploy it from depth it can allow the expanding gas to keep from blowing a hole in your SMB, It should be large enough to give your dive buddy sausage envy, Being able to deploy it from 15 feet should be a minimum skill. You may get separated from your groupand have to do a bluewater ascent in anarea that has boat traffic, so if you wait until you are at the surface, you are more at risk from getting hit by a boat. Of course just because you deployed your SMB, do not assume all the boats will see you or even know what it is. And of course if you have a deco obligation, deploying it sooner would alllow your pick up boat to spot you sooner than later.
Edited by MNJoe, 05 July 2016 - 05:39 AM.