This document could do with an explanation of some of the technical terms used in a glossary at the front of the document for the less familiar with terms such as 'Bifurication, isophase, delineate'
The references to use of VHF radio for contacting European lock/bridge keepers give no language words that may be needed nor translation of phases on signs that may be encountered, or are we to assume everybody speaks English?
I found confusion between similar night lights i.e carriage of dangerous loads and carriage of inflammable materials and carriage of mateials hazadrous to health.
The multiple choice test at the back does not tell you which are the correct answers.
In the online RYA test I scored 73% before I read this book (by pure intuitive guesswork), and only 63% ater reading it! Oops!