Ed, I'd second Cesar's question. Just imagine if your Garmin was working at Fish Day. You most likely would have held back more than necessary and ended up 4-5 minutes slower.
Cesar, people have suggested that I might want to wear a watch for one reason or another but I can only recall one race where I did wear a watch. It was a race where there was no official timing – we were in charge of recording our own times. The only time during the race I looked at my watch was in the first few steps, to make sure it started. I didn't look again until after I crossed the finish line.
I've never felt the temptation to look at my splits on a race course. If splits are called out, it's a nice thing to hear, just for peace of mind. If not, it's more reason to work on that inward focus, which is probably better than listening to splits anyway. Seeing as I try to make a habit of not checking splits on training runs, I don't miss a thing on race day.