He was referred to in contemporary books and journals as "the father of British sea painting", but was eclipsed by his contemporaries, the Dutch marine painters Willem van de Velde the Elder and his son Willem van de Velde the Younger, who for a period dominated the London market.

His style can also be identified by its reliance on a relatively narrow palette, principally black, greys and greens, and by minor details within his paintings, such as the way he depicted flags and gilding.

[8] He was one of Britain's earliest marine painters, and was referred to in contemporary catalogues and books as "the father of British sea painting".

[7] Vertue wrote that Sailmaker "employed himself always in painting views, small and great, many sea-ports and ships about England" and calls him "a constant labourer", which suggests that he produced a large body of work during his lifetime.

[12] At the end of his life, Sailmaker was living in a house along King's Bench Walk in the Temple Bar area of the city of London.

[2][15][note 4] Sailmaker's surviving works reveal that he painted in a basic version of the Dutch style, making portraits of ships side on, stern and bow view.

[17] An advertisement for an engraving by Sailmaker in the Term Catalogue of November 1692 stated:[18] GLORIA Britanniae or An exact draught of the large Ship, called the Royal Prince in several postures, drawn by Mr. Isaac Saylmaker.

He described the work as "this uninspired group of ships and galleys" which "indicates admirably how little was the English painter's skill three years before the younger van de Velde died".

This little man imploy'd himself always in painting views small & great of many sea Ports & Shipps about England, he was a constant labourer in that way tho' not very excellent.