Se7en once bubbled...
Actually, for an OW diver, a depth guage is really useful, even without a watch.
With a max depth of 60 ft (which is 18 m, not 28m), you have the best part of 60 minutes bottom time, depending on which tables you use. Therefore, for a dive in this range, dive duration is going to be determined by air consumption, not NDL.
Therefore, a depth guage is much more important than a watch - as you know that if you stay shallower than say 50 feet, you don't have to worry about NDLs. However, a watch without a depth guage is pretty useless...