Both are sh*t unless held up high above water inc waves and splashing.
Studies coming out are suggesting if you go over and have one strapped to your chest most of the time it will be doing nothing. These units are very prone to being blocked by water, even very little of it.
So hold them up high and aim PLB antennas at the sky, AIS antenna at the boat.
Stick a silver rescue blanket in your McGyver life jacket. No water issues and will make you more visible to radar, even some quite a long ways away.