glenb are you using any form of electronic system presently? I'm not sure of the cost of Genav but I did implement Openflyers for a school some time ago. It was a significant improvement over the old paper book and allowed the instructors much better access than before. It took a little time to get used to but was fairly quickly indispensible - as evidenced by the comments if it was off-line for some reason!
At that time Openflyers was open-source PHP/MySQL based and so there was no initial purchase cost. I did some work on it and contributed back to the project as one might expect. The model later changed to a commercial one and I chose to withdraw from contributing so I've not looked recently but it may be that the previous version - which was eminently satisfactory for most purposes - is still available and could suit your operation. Alternatively they offer an on-line commercial product that I know some organisations make use of.
Never having used Genav I'm not suggesting this would be any better or worse, merely that if the cost is high it's possibly worth checking a few other options out.
FP.