From Preston Chronicle, Sat 29 June 1839

DIVERS AT BLACKPOOL.
  An operation of great interest is now going on, and will probably be continued for some weeks, in the recovery, by a party of divers, of part of the cargo of the Crusader, a vessel which was wrecked on the Horse Bank, near the month of the Ribble, in the tremendous storm of the 7th January last. This vessel left Liverpool on the previous day laden with a general cargo for the East Indies. The crew were all saved, and our readers will remember the account we gave at the time of the plunder by the Fylde wreckers of part of the cargo which was washed on shore.
  A portion of the vessel still remains together, deeply imbedded in the sand, and at low water part of it is visible. It was ascertained by the examination of a diver that a good deal of the cargo was still there, and the party now at work are engaged by the underwriters to recover it. In the course of the last fortnight they have succeeded in getting up a considerable number of bales both of cotton and silk goods. Two small vessels are moored immediately above the wreck, containing the necessary apparatus for the divers, and for hauling up the goods; there are three divers, and not less than thirty men in attendance upon them for the various purposes of working the air-pump, attending to the signals, and hauling and stowing the goods, etc.
  The head of each diver is covered by a helmet of thin sheet copper, large enough to admit of the easy motion of the head, and capable of containing between six and eight gallons of air. The helmet comes pretty far down on the breast and back, and has in front two eye-holes, covered with glass, protected by brass wires. The copper helmet is attached to a water-proof canvass jacket, by means of rivets, so tightly fixed that no water can be introduced to the body of the diver. The junction of the helmet and jacket is stuffed, so that it may clasp the shoulders of the diver firmly. A leather belt passes round the diver, to which are attached two weights - one before and the other behind - each weighing about 40lbs. These weights are attached in order that the diver may descend with facility; but, in case of any accident occurring when he is at the bottom, the belt is fastened with a buckle in front, which he can instantly unloose, and rise to the surface after the dropping of the weights.
  The diver is supplied with fresh air by means of a flexible waterproof pipe, which enters the back of the helmet, and communicates with an air pump, wrought above in the vessel from which the diver descends. The tube passes under the left arm of the diver, and, turning upwards, enters the back of the helmet, being so contrived that the fresh air is made to impinge against the glasses, which, in a great measure, prevents their being dimmed by the moisture of the breath. From the back part of the helmet, there is likewise led an eduction pipe, to allow the escape of the breathed air. In order that the diver may give notice to the attendants at the top, when he requires a hook, tackle, bucket, or any difference in the supply of fresh air, he is furnished with a signal line, which passes under his right arm. That he may be as comfortable as possible under water, he puts on two suits of flannel, above which he has a complete dress, in one piece, of Mackintosh's waterproof cloth. The waterproof dress covers the body entirely - the only apertures being at the neck and wrists. The opening at the neck comes comes well up, and is tied round tightly with a bandage; which contrivance together with the pressure of the air in the helmet, prevents the water from entering the helmet, and the wrists are, likewise, tightly bound with bandages.
 The diver is thus enabled to remain for five or six hours at once under water, all the while perfectly dry, his motion being rendered quite steady by heavy weights attached to his shoes. With this apparatus, the divers may now be seen daily at work at the wreck of the Crusader: they plunge into the water, and, shortly afterwards, bundles of twist, bales of goods, etc., externally blackened and torn, are drawn up from the sea. The situation of the diver is known by the bubbles on the surface of the water. The work is evidently very severe, and the divers come up much exhausted.

Postscript: The above seems to be a description of something similar to what was known as the "open" diving apparatus, patented and used by the Deane Brothers from the early 1830s. The visit of Charles Deane to Liverpool in 1836 was followed by a sale in 1837 of a Deane diving apparatus to the Liverpool Dock Board - these early Deane sets had a helmet with two glass viewports (later ones had three). So perhaps divers from Liverpool were involved in the salvage of the Crusader.
  The "closed" version was introduced by Augustus Siebe in 1837, following input from others. His standard helmet had one forward facing window and two side windows. It became the basic design for many years afterwards.