An avid sailor, Signac was predominantly known for his vibrant paintings of seascapes and ports. It was Pissarro who urged him to try the medium of watercolour, understanding how the practicality and uniqueness of the medium would be beneficial to his friends’ artistic practice. 

In just a few minutes you can take notes that would be impossible by other means – the fluidity of the sky, some transparent effects, a mass of small pieces of information that cannot be conveyed working slowly [ Pissarro to Signac in a letter dated August 30th 1888]

It wasn’t until some years later, in 1892, after the death of Seurat, his partner in Pointillism, that he heeded his friend Pissarro's advice and made his first proper trials in watercolour. It was during one of his many trips on his boat L’Olympia, and after a few initial attempts, by the time he got to his destination in the South of France and whilst awaiting his painting equipment, he got to grips with the medium. Showing a remarkable aptitude for the medium, he was ‘immediately capable of exploiting its possibilities’  (Marina Ferretti Bocquillon, Paul Signac, a collection of watercolors and drawings, p.14, Ed. Abrahams Inc., New York, 2000 ), henceforth replacing his pencil studies in favour of watercolour to better convey the landscapes and light of the French south in colour. 

Around this time Signac renounced the use of oils for Plein air painting, preferring watercolour as the intermediary medium. This allowed him to travel unburdened by equipment, to record the wonders he saw, the effects of light, colours and then use his notes when back in the studio to produce the more methodical, intellectual works in oils. He left a colourful trail of his travels in his carnets and his letters to friends which he would annotate with watercolour. 

An enthusiastic sailor, Signac travelled on many occasions to Brittany and Normandy in northern France, usually sailing on his boat, l’Olympia. From 1924 through to 1930, he spent his summers at Lézardrieux in Brittany and in 1931 he bought a property in Barfleur, Normandy. Harbours and boats had long held a fascination for him and were a constant source of inspiration for his painting. He would spend many contented hours sketching by ports and quaysides and once he had mastered the use of watercolour he saw no need to take anything else with him other than his pocket paints and a notebook, painting fluidly and with ease, finding a harmony in the pure colours. 

Signac had long admired the work of Johan-Barthold Jongkind and was a collector of his watercolours. They had a shared affinity with water and boats. In 1899, Bernheim-Jeune held an exhibition of over 50 of Jongkind's watercolours which left a deep impression on Signac, who wrote several pages on the works in his journal.  

Signac appreciated Jongkind's subtle technique, his shimmering style which translated the energetic and emotional character of the scenes he depicted.

In 1927, he published a monograph on the artist, with particular focus on his watercolours and drawings. 

Françoise Cachin pointed out that when he writes about Jongkind as a watercolourist, he is, in fact, writing a virtual treatise on the art of watercolour (Françoise Cachin, P.Signac, Paris, Bibliothèque des Arts, 1971, p.116)

‘[…] from 1863, with motifs of Honfleur, d’Anvers, de Rotterdam, Paris and surrounding areas, starts the most beautiful series of of watercolours in the world.’  ( Signac about Jongkind series of Watercolours)

In Jongkind he recognised a kinship in his use of light and colour in the medium of watercolour, down to the effect of leaving the white of the paper to show through the paint and also leaving gaps in the paint revealing white paper, leaving the colours to reveal their intensity and synthesize.