A bathing machine was a wheeled shed, inside which women shed their clothes; a horse pulled the machine some way out from the beach, and the women got cautiously down into the water. This was, like the Assembly Rooms, an institution that spread to Lyme from fashionable Bath, even though Bath is not on the sea. A leading merchandiser of these machines from Weymouth, Ralph Allen, was a friend of Henry Fielding, and is said to have been the model for the good Squire Allworthy in Fielding's Tom Jones (though that was written as early as 1745).

There were four bathing machines on the western part of the Lyme beach in the first decade of the 1800s, later six or eight. Establishments such as the old Three Cups Inn and England's Baths had a machine or two for use by their customers.

When ladies went to bathe, a bell was rung, whereupon men had to leave the beach. Later, men also were using machines—separate ones—and they had to be at least fifty yards from the ladies'. And, lest you were tempted to sidle around by sea, rowboats were forbidden to come closer than a hundred yards.

Yet Captain Marryat must have stolen a good long look, for he did a drawing, from which in 1819 his contemporary the great satiric artist George Cruikshank made an etching (reproduced on page 29 of John Fowles's Short History of Lyme Regis). It shows a bathing machine being pulled by a horse (and male rider) into the water, and several others with horse and shafts removed; from their doors naked ladies climb down the steps or dive into the water, in which others frolic, while one of particular plumpness is being lifted out by her two clothed maidservants. The scene fits this Cobb end of the Lyme beach, except that in the right foreground is a pile of rocks, or perhaps a high jetty, on which a gentleman with a top hat, not in the least attempting to hide, observes through a telescope. He perhaps represents the projection of Captain Marryat himself, spying from the window of Madeira Cottage, three hundred yards back along the Marine Parade.

At the end of the nineteenth century the machines were superseded by tents.