Wendy, the only problem with a sight bob is that some anglers use it as they would a float by fishing static, they may as well use a rod rest as well.
If you watch Graham use one you will see he is always working the line, always taking up the slack, he uses it to catch the drift, slackening and tightening when the conditions demand it, in short he has total control.
There is a degree of skill in using a bung on rivers and still waters but no skill if your just sat their waiting for it to go under.
You don't exclusively need a bung for an indicator, many anglers use a dry fly instead on a short top dropper, it is just as good as a bung, cast better and best of all a fish could and often will take it.
If you do use a bung then use it to your advantage and don't just stand or sit there watching it waiting for it to disappear.
Good luck BC.
PS If you see old marsbar getting tired and just sat there watching his float without any hand movements O'oooooo!!!.....
.....give him a yell and tell him to do it properly. Keep those hands and fingers moving lads and ladies.
Hope to see you all tomorrow but things are looking grim at the moment.