From Picture of Liverpool: Starnger's Guide written in 1834
This is a great public accomodation provided at the sole expense and risk of the proprietor, Mr Thomas Colgan, and is said to be the largest establishment known of this kind. It is constructed similarly to the hull of a vessel, and is buoyed up by air-tight chambers. The water being admitted through an iron trellis, and escaping through a corresponding one at the opposite end, is perpetually changing with the current in the river.
The extreme lenght of the vessel upon the deck is 82 feet, the width 34 feet, and the dimensions of the bath are 80 feet by 27 feet.
The bottom is an inclined plane and gradually varies in depth from 3 and a half feet at the shallow end to six feet at the deeper end. No bath could be better adapted for learning the art of swimming than this which has all the advantages of a running and sufficiently deep stream, without the slightest danger. Around the bath are gangways, which comunicate with numerous neat and convenient dressing rooms: and for the purpose of private bathing a screen in front of a portion of the dressing rooms, so that individuals may descend into the water unobserved. Besides this there is a small private bath, and those gentlemen who prefer swimming in the river are allowed to go through the door on the side of the vessel which may happen to be opposite the Cheshire coast. There are two spacious cabins, one at the stern and the other in the middle regularly supplied with newspapers. A variety of excellent refreshments may at all times be had here. The upper deck which is surrounded by rails, and commodiously furnished with seats and tables affords a most pleasing and ever-varying prospect.
During the sumer the bath is usually moored opposite Prince's Parade, and in the winter is stationed at Wallasey Pool. It was launched on the 11th June 1816