New picture
In the second edition 59 pictures have been replaced by better quality in respect to color and brilliance. Despite many suggestions and offers only a few photographers happen to make good pictures of aquatic macrophytes, especially of submerged ones.
Scuba divers form the exception on this, they often produced very nice pictures of macrophyter and offered them to be used in the field guide. They were refused anyway because the pictures are, according to the author, not giving a recognizable view of the plants to most people, except for divers of course. N.B. The author is an experienced scuba diver and underwater photographer himself.
improved keys
Some keys to identify species are improved after suggestions of users. Also the errata in the first edition are updated in the keys of course.
More details
Line drawings of details or placed next to the keys to show what is meant by the properties described. In the second edition 73 new or improved drawings were added and the main key also was illustrated by explanatory drawings. At the pages with species descriptions also 8 new or improved drawings were added.
Actualisation
Several species described in the first edition, but unknown for The Netherlands by then, were found since the publication of the first edition.
Taxonomy has been updated according to the new edition of the standard flora of The Netherlands (Van der Meyden, 2005: 'Heukels' flora').