Diving Bells had been used to get access to wrecks for salvage.
Initially they relied on the trapped air - so were only able to be used
for a short duration and in shallow water. This was overcome by either
sending weighted barrels of fresh air down, or by pumping air from the
surface. Bellows air pumps were rather ineffective, so it was only when
piston air pumps and hoses capable of sustaining higher pressures (made
of Mackintosh material) became available and reliable that pumping became
practicable.
The Deane brothers (Charles and John) developed the concept
of a diving helmet - essentially a small diving bell that fitted over
the head with glass windows. This was fed with air from the surface and
was open at the bottom, so the diver had to stay upright. Their
patented apparatus was used in wreck salvage from the early 1830s.
The next step was to use a closed suit - with several early
patents around 1835-7. The eventual design was improved by Augustus
Siebe - standard diving dress - that continued little changed from 1839
on.
Some records of historical salvage by divers in the Irish Sea region.
Adelaar 1728, "diving engine", Barra.
Belgioioso 1783, Kish Bank, pioneering Diving Bell salvage 1783-7.
Pelican 1793, Mersey, attempted use of "diving apparatus" 1798.
Enterprise 1803, Mew Island, Diving Bell salvage 1829, then pioneering and lucrative helmet diving 1834 by Deanes.
Liverpool 1836, Visit by Charles Deane to Liverpool, with diving on dockgate and wrecks. [also Deanes Diving Manual]
Intrinsic 1836, Kilkee, Charles Deane salvaged (details).
Aimée Rose 1836 Alderney [Channel Islands], first recorded death of a helmet diver.
Scotia 1838, John Deane dived near Penmon
Lady Charlotte 1838, John Deane and others salvaged near Cape Clear.
Crusader 1839, divers salvaged (details) near St. Annes.
Byron 1839, divers (H Abbinett) used gunpowder to disperse wreck in Rock Channel.
Young William 1802, guns recovered 1839 near Llanddwyn by John Deane, also info about Skerries salvage.
PS Mountaineer 1841 refloated 1842 in Swellies using a diver.
Prince's Dock 1844, diver recovered copper bar.
HMS Racehorse 1822, divers salvaged 1844, Langness.
William Turner 1845, divers salvaged 1845 Caernarfon Bar.
Margaretta 1843, divers salvaged 1845 and 1849 Cardigan Bar.
PS Ajax 1846, salvage dive attempt near Mewstone.
Salvage by Jones Bros of Bangor 1845-48: Antelope 1844, Mary of Douglas 1845, Chester 1845.
Cymro and Cymraes 1847, divers salvaged 1848 Puffin Island.
Ocean Monarch 1848, salvage diving, Liverpool Bay.
Mary Scott 1841, salvage dive 1850
PS Queen Victoria 1853, dive report, Howth.
Cheshire Lass 1856, raised at Chester by a diver from Bangor.
Pomona 1859, divers recovered bodies.
See "Life and Death on the Royal Charter" by Chris and Lesley Holden for detailed reports of salvage diving on the Royal Charter [wrecked 1859] from 1859 on [divers from Liverpool and Whitstable].
Charles Holmes 1859 1860 salvage diving.
PS Lyra 1861, divers salvaged
Doris 1866, diver injured [also report of his dive salvage on Royal Charter]
PS Boubolina (ex-Colonel Lamb) 1867, divers surveyed
Iron clipper James Crossfield 1867, Langness, divers salvaged 1867, 1870, 1874.
Liverpool Salvage Association 1875-, salvage vessels, diver anecdotes.
PS Athlumney, SS Fawn,.. 1887, Coal Rock diving
SS Angola 1887, night diving salvage
SS Mail 1859, divers using explosives in 1893.
Alice Linda 1913, diver investigated wreck
SS Glencona 1926, diver accident.