As promised, here are two pics of how it is attached to the back of the chair. I removed one screw from the back of the seat and used it on the hole at the top end of the black plastic bracket. I then used plastic wire ties to hold the lower end of the bracket against the seat (I didn't want to drill holes in the aluminum bar supporting the back of the chair.
The red gizmo to the left of the fire extinguisher is a man overboard strobe. When I was anchored at the Chesapeake Bay Bridge Tunnel at the mouth of the Bay one night, the current was ripping through the bridge pilings. I thought to myself, if someone fell overboard, and was swept out into the darkness they would never be located until the CG found the body floating the next day. So I added the strobe. If someone goes overboard at night, the strobe follows them overboard. The strobe will float near the man overboard until the anchor rode can be cut, the motors started, and the person (strobe) chased down. Yes, I said "CUT" the anchor rode. In December, with water temps in the 40's and air temps in the 30s or 40s, getting someone back into the boat quickly is more important than an anchor. BTW, I also carry towels and a sleeping bag, so that the person who fell overboard could strip, dry, and get warmed up while we traveled the 12-16 miles back to Little Creek Naval Base.