Target Practice
I don't know about other people, but I tend to use scuba divers as targets. Sure, they're slow, and it's no fun after the first two or three shots, but they'e cheap and plentifull !
OK THIS IS A JOKE DAMNIT ........
Once again, being the elaboritist that I am, I use different setups ....
Favourite is plastic bottles - any type of plastic container that floats, really. Half fill them with water, and practice upwards shots. Be carefull where you do this.
Then I'm trying to set up a net system - I've got about 200 kg's of small mesh fishing net (holes about 3mm across) that I can use for this, so I'm trying to rig something .....
Maybe set it up this way - rig a square piece of net that's as big as needed, suspended from floats with fishing weights at the bottom end. The have another one of these 30 cm or so behind it to catch the spear .... mmmmm what do you guys think ?
Then I had a nice idea some time ago. Working in the computer industry and going to a fair amount of conferences, I get my gritty little paws on a lot of stress balls - the type made from some or other foam and about 10cm accross. Punch a hole through one, pass some chord or line through it, tie the other end to a weight and voila ... a semi - floating depth-adjustable very small target ... it improved my shots a LOT. I can now go down to 20 meters, aim, fire and hit it at 4 meters with either hand. Takes some practise to do that. I've used my small gun on it as well, but it doesn't quite go that far - can only hit it fair at about 2.5 meters (gun is only 65cm ...)
The stress balls tend to go quite chunky after about ten good hits, but it's normally not a lot of stuff you have to pick up afterwards. And as I get them from other companies, it's cheap