Steamboat
Similar boats were made in 1785 by John Fitch in Philadelphia and William Symington in Dumfries, Scotland. Fitch successfully trialled his boat in 1787, and in 1788, he began operating a regular commercial service along the Delaware River between Philadelphia and Burlington, New Jersey, carrying as many as 30 passengers. This boat could typically make and travelled more than during its short length of service. The Fitch steamboat was not a commercial success, as this travel route was adequately covered by relatively good wagon roads. The following year, a second boat made excursions, and in 1790, a third boat ran a series of trials on the Delaware River before patent disputes dissuaded Fitch from continuing.
William Murdoch
Boulton and Watt had been involved in a minor way with attempts to apply steam power to boats, providing in 1807 for Robert Fulton the engine for "North River Steamboat", the first steamboat to run on the Hudson River, (the boat later referred to as the "Clermont"). Murdoch was primarily responsible for designing and building this engine and for agreeing technical details and designs with Fulton, who also worked on the design of the engine. Boulton and Watt also provided engines for a number of other marine vessels. However, it was not until the purchase of "The Caledonia" by James Watt Jr. in 1817 that they became seriously involved in the marine engineering business. The task of refitting "The Caledonia", building and installing new engines and boilers and making her seaworthy and efficient in fuel consumption was a difficult process and Murdoch, although frequently suffering from fever and rheumatism, directed this. By August the vessel was able to be tested on its intended route, from Surrey Commercial Docks, London to Gravesend and at first made 8 miles per hour (mph). During its sea trials Murdoch carried out experiments on "The Caledonia" to measure the effect on fuel consumption and speed of changes in the depth of the paddles and whether one or both engines were used. This resulted in an increase of speed to .