Then scroll down to the "How to Download Your eBooks" section and select your platform. Click on the appropriate "get it from" icon and install it on your system.
When you launch the reader click on the "Sail" or "Power" section and then the "Communications" section to get to the VHF books.
Select the VHF Handbook E-G31 and click the sample option.
Once this has downloaded (it may take a while) open it and scroll to the end to try the audio on the last page (39) by clicking it's play button.
If all that works and you have a microphone on your system then you should be able to use the eBook version of the course book.