Cedric,

Excellent post! Have some green :-)

A few more points to consider (some already mentioned, but I prefer stronger wording):
- spare mask
- spare reel and SMB (agree on colours prior to dive to indicate trouble)
- spare computer and/or 2 sets of tables
- spare torch
- spare set of cutting device
- bailout for every! stage of the dive
- slate + SMB to send up for communication with surface

Nothing new in the list above, just for completeness' sake.