Same way i hunt birds with a shotgun: i point.
The situation develops fast up close and all my focus goes into 1) tracking 2) balance 3) pointing. All of these sort of melt into one another, if i get the proper rythm it flows into one movement. If i add aiming into that i miss, and that is because i then start to think about aiming. And thinking too much often lands me into trouble
Same with my spearing: tracking, balance (smooth glide), pointing.
I'm not going to brag about a lot of fish kills because i'm really a newb to spearfishing, but every time i do have the opportunity i get the same feeling/rythm as with my shotgun hunting, only here it is easier because the 2 first steps gets me closer, making pointing a lot easier.
The trick to pointing is selecting a spot on the target and point at that spot.
If i just point at the target i am going hit just that, the target. That works for birds while using a shotgun because i make a good hit if i cover the target with pellets.
With a single thin projectile like a spear i have to select a spot on the target (eyes, gills etc depending on the angle i got to the target) and point at that, otherwise i am just going to put a spear right thru the center of the fish and make a mess. Tracking while doing a smooth glide (or having a nice position) makes focusing on a spot "easy", i do not think, just point like i would point my finger at that spot and squeeze the trigger.
It is the same thing if i either stalk or the fish approaches while doing its mind-reading routine (it sort of picks up on my intention, probably based on my body language like really eyeballing them while pointing a large, sharp object), the latter requires more patience before starting the show.
I do not shoot at fast moving fish because i am not good enough yet at visulaizing the necessary displacement of the killspot the same way i would aim ahead of a fast moving bird with my shotgun.
But then again, this habit of mine is probably based on the way i was trained with firearms, and i just adapt the technique to get the same feeling of flow to shooting a speargun. Someone else might have quite a different way of doing things that works equally or better for them.
