...I guess there isn't a textbook DIR way to do this, ....
There is...... in a pocket or between diver and BP. But since your question is in the HOG forum, you get more variety....

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...I guess there isn't a textbook DIR way to do this, ....
SMB alone between BP and diver. Spool in pocket or butt ring....... when you need to deploy, you put the spool on the smb, and voila.... shoot the bag.![]()
Pocket on my drysuit or wetsuit (x-shorts)