So we can almost pet the fish, join the school, the giant trevally comes right at you, etc
Should we spear them on CCR or SCUBA? I would say only away from popular wrecks and reefs. I don't see anyone shooting deer and eagles in the local community parks anymore, amen to that. Maybe out in the proper woods during season.
Certainly dive spearing happens (including on rebreathers I imagine) in Washington as there is a ton of fish and habitat. But not in the local dive parks, you could get fined or saltwater in your gas tank for that.
CCR seems risky, a worthwhile fish could be big enough to pull a diver deeper or shallower. On CCR that could dangerously affect loop volume and ppO2, distract from ppO2 monitoring, task load away from running the unit. If it's small prey I gotta ask why even (unless it's invasives control)