The training blob comes rolled into a 7x12cm bundle and weighs less than 150g, held tight by a loop of sewn-in-place bungee. I used it with my usual finger-spool, looping the string through the stainless-steel ring firmly stitched to the bottom of the blob. The larger DSMBs have a webbing tail, with the ring at the end of the tail.
Inflating the training DSMB has been well thought-through. You undo the bungee and unroll the short buoy to reveal a one-way valve into which you simply pucker up and blow.
The buoy is sized to fill easily with one big breath and fills to give a sausage 1m long and 8cm in diameter.
The advantage when shallow and in training is that the gas going into the buoy is coming out of your lungs, so the net change in buoyancy is minimised, increasing only slightly because the buoy will be higher than you are.
The business end with inflator-valve, dump-valve with big toggle, line-attachment ring and bungee cord.
No big buoyancy change equals no scary upward movement, and that means confidence gained more quickly. I found it possible to launch the buoy from just a metre down and get it properly inflated with no drama, and it inflates just as easily on the surface if necessary.
Then, when you’ve mastered the pucker and blow, you can learn to use a low-pressure inflation-hose on the valve to inflate the buoy even more quickly and smoothly.
And I have to say that it’s the best way to inflate a DSMB I’ve yet come across. You simply push the end of the inflate valve into the open end of a low-pressure inflation hose, and the sausage will fill fast enough for you to release it under control before the effects of its positive buoyancy drag it from your hands.
You can use any inflator hose, the one from your suit or your BC, or even a spare fitted specially for the purpose. The hose fitting doesn’t make any difference: universal, Apeks and AP all worked for me.