So far, bell bounce (now called TUP diving) is only being done off DP Sat boats in the North Sea, basically using one of the bells and one chamber, although at least one of the big boys is considering making a dedicated system up, and a Norwegian IRM company was ‘marketing’ a dedicated system which consisted of the bell, and a small TL connected to a hyperbaric lifeboat with a couple of locks, to get around the issues of escape, etc. (There’s quite a good ‘animation’ from a company called Nsea on the internet, for their TUP system which used to work in the southern sector of the North Sea. It eventually had to move the system to another region, as, amongst other issues, the only escape the system had was to either emergency deco to surface, or blow everyone down and get them in the bell, launch it and drop the weights...)