Certainly not my experience - the log book was mine to keep safe.Thanks all for the descriptions. The instructor collected our log books at the end of the class. Unfortunately, I didn't think to look in it for the ow dives.
Only thing I can think of is it was to allow them to fill the relevant sections up at their leisure as opposed to an entire class at once.
As others have mentioned, the only thing you won't have done is navigation but if you are reasonably comfortable with a compass on the surface, underwater is virtually no different apart from counting fin kicks instead of strides.
The best thing is getting all the skills out of the way before the last dive (if you can). Then the last dive is simple - plan and execute a dive. Simple plan such as overall plan, turn point (gas or time) etc, go dive it and watch the scenery that you have been to busy to look at prior to it.