Diving knives have been issued to the RAN divers and to specialist Army units.
The heavy duty knife such as the one by Siebe Gorman was on issue to various units up until the 1980's and may still be held in stores.
More recently lighter style diving knives have been used
This knife most likely dates to WW2.
This Greg Steel divers knife sold at auction several years ago. I would appreciate it if the current owner would contact me so that I may get some better images of it.
The only recent example I have seen does not carry acceptance marks.
This Siebe Gorman Divers Knife is in the Glaister Collection.
Markings on the Knife