Some of the places online, make it a big deal that they have soccer referee specific watches, and I am sure that they are better than the standard ones I use. I know that there are ones that countdown and then count up once the time has been consumed so you know how much additional time you have added. There are others that look almost like those athletic stop watches that track and field people use and have huge numbers so that it is easy to read.
For me, I decided on going with 2 watches (I heard someone tell me that it is recommended to go with two just in case one goes bad and you do not have ARs that can back you up). So I trotted to Kmart and ended up buying two Casio watches. Not both the same because that would have been silly in case the design had a problem that I did not like. The two models I bought were a Casio W-752 and a Casio W-93H. Total cost was around $35 for both (they were running a special of sorts, regular price is more like $45 for both).
The W-752 has a long life battery (it said 10 years, but I am sure it is not that long) and had larger numbers, so I wear that one on my right (I am a lefty and use a wrist strap whistle on my left hand). I normally wear my watch on my right so that is where I go most of the time to consult how much is left. It has a countdown timer but no bells and whistles with regards to that countdown timer. Here is a picture of the watch:
The second watch is smaller (the W-93H) but I fell in love with it almost instantly. And why you ask? Because its countdown timer has a couple of features that I was not expecting (not for $15 at least). There is one to immediately restart, so that when it hits 0:00, it begins at 40, or 35 minutes, or whatever you were at. I can see this option working if you want to add time, and you say, ok, I am going to add two minuites, so we go to 33:00. I have not used that function yet (I did 4 matches this weekend, 2 in center and two as an AR). The other feature it has is awesome to tell you the truth. You can have it beep when the countdown timer hits 10 minutes remaining, 5 minutes and then every minute until 1, then every 10 seconds until 5 seconds, and then every second until it is done.
I find this feature to be very useful as I do not need to be looking. Today, when it beeped for 10 minutes, I already knew that was the 10 minute beep, the second one told me we had 5 remaining and I did not look at my watch until it started doing the 10 second chirps. To be truthful, I find the 10 second (at 50 seconds, 40 seconds, etc) to be overkill, but otherwise an awesome watch. The numbers are smaller, but still a great buy for $15 at Kmart. I might go get another one for when this one dies or cannot be located. I certainly hope that doesn't happen soon!
