The Deep Sea Defender’s red back pack was connected to him with a rubber band that came with the figure. A clear plastic tube connected from the figures ‘aerial’ weapon to the peg on the backpack. 

The peg was supposed to be used to attach to GI Joe figures backs but it was a clever idea to adapt it to this figure that had no peg hole on his back.

The pack also came with the German version of the figure ‘Leguan.’

The red pack was supplied with the GI Joe Jump set in a different colour. There is more about this on the Deep Sea Defender page. Despite being designed as a jet pack it does not look out of place on a Deep Sea figure as it could easily be though of as an Oxygen pack or underwater propelling pack.