Okay. I was taught not to answer a question with a question, but there is one which is crucial to answering yours
How deep is the drift dive?
TBH I would be doing a drift dive more than 30m because it is a waste of Helium

If you need to do a 30m drift dive, then I would use a 45m spool which will have plenty of give to take into account the running current.
Hope that answers your question.