Bol dates this painting around 1615 on the evidence of the costumes, and regards it as the earliest known work by the artist, who began his career in Haarlem as a cabinetmaker and later moved to Amsterdam, where he took up painting. Here we see the Inner Amstel looking south. In the foreground is a row of mooring posts, with the boom house to the right. The opening in the palings allowed smaller vessels to sail in and out of the city in the daytime. The boommaster’s job was to lay a boom across the entrance when the bells on the city gates sounded in the evening and remove it again the next morning. The boom house also contained the office of the collector of excise duty on goods being brought into the city. A jetty led from the house to the west bank of the Amstel. The waterfront in this painting disappeared around 1657, when the city government decided to extend the system of concentric canals to the east to link up with the Amstel. It was a massive undertaking, and involved the demolition of many of the riverside buildings.

Two ships, in particular, stand out in this painting. The first is the yacht moored to the palings, which is flying a flag with the arms of Amsterdam and might be a pleasure yacht, a ferry or an official city yacht. The yacht on the left is unusual in that it does not have the gaff or spritsail rig common at this period, but a jibheaded rig with loose-footed, triangular sails. This probably originated in Portugal, and was introduced into Holland at the end of the sixteenth century by Dutchmen in Portuguese service, like Jan Huygen van Linschoten and Dirck Gerritsz. Pomp. This is the earliest known painting of a vessel with this rig.