[2] Van Rysselberghe was one of the founders of the Brussels progressive association Les XX, and played a leading role in the communication between Belgian and French artists.

When, in 1886, during the last major Impressionist exhibition Georges Seurat presented what would become the leading example of pointillist technique, namely A Sunday Afternoon on the Island of La Grande Jatte, Van Rysselberghe initially voiced reservations about it in an exchange of letters with his friend Emile Verhaeren.

[3] Sailboats and Estuary is typical of both the theme and the neo-impressionist style that Van Rysselberghe had learned directly from the movement's leading artists: he started entirely from the theory of color as defined by Seurat, more specifically, his "doctrine of simultaneous contrasts", which he had studied extensively.

He meticulously juxtaposes unmixed dark blue, crimson, yellow, green and white brushstrokes against each other in arithmetically determined proportions, as in a kind of mosaic.

A reviewer of the Parisian art magazine La Plume wrote of the painting on April 1, 1898, "it shows in all its facets the full luminous beauty that the new pointillist school can offer.